<%BANNER%>

New Ventures in Heterocyclic Chemistry

Permanent Link: http://ufdc.ufl.edu/UFE0044867/00001

Material Information

Title: New Ventures in Heterocyclic Chemistry
Physical Description: 1 online resource (138 p.)
Language: english
Creator: Kovacs, Judit
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2012

Subjects

Subjects / Keywords: benzotriazole -- dyes -- macrocycles -- nitroso
Chemistry -- Dissertations, Academic -- UF
Genre: Chemistry thesis, Ph.D.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: This thesis describes the synthesis of small molecular libraries of potentially biologically important molecules utilizing standard benzotriazole methodology and also the synthesis of heterocycles for use in material sciences. The aim of the project described in Chapter 2 was the development of a methodology allowing for the synthesis of a library of dye-labeled nucleosides without the use of protecting groups. N-(4-Arylazobenzoyl)-1H-benzotriazoles were prepared in 79-86%yield. Dye-labeled nucleosides were obtained in 30–79% yields by treating N-(4-arylazobenzoyl)-1H-benzotriazoles with appropriate nucleosides. Similarly, N-(4-arylazobenzoyl)-1H-benzotriazoles afforded dye-labeled threoninol conjugates in 55–89% yields. All novel products were characterized by NMR and elemental analysis. Chapter 3 details the synthesis of amino acid conjugates of quinolone antibiotics. The moderate reactivity of acyl benzotriazoles compared to acyl chlorides allows for synthesis without the use of protecting groups.Coupling free amino acids with the benzotriazolides of nalidixic acid, oxolinic acid, cinoxacin, and flumequine was achieved in 43-86%yields. Chapter 4 describes results obtained towards the synthesis of unsymmetrical diketopyrrolopyrrole dyes. The reaction between bis(imidoyl)chloride and substituted ethyl 2-phenylacetate gave the symmetrica ldye, but bis(imidoyl)benzotriazole  was found to be unreactive probably due to steric hindrance. Bis(imidoyl)imidazole however, was found to be a promising candidate for the ultimate synthesis o funsymmetrical dyes. Chapter 5 describes progress towards the synthesis of quinoxalino ligands which potentially may be used as metal scavengers in the purification of metal-catalyzed reactions. The incorporation of various substituted quinoxalines into tetraazamacrocyclic structures, using a metal-free synthetic protocol, should allow synthesis of useful compounds withcomparable or superior properties. Despite being an incomplete work, it of fersa prospective route towards an efficient synthesis of aza-crown macrocycles. In Chapter 6 a new class of geminally-substituted nitroso compounds, i.e. a-benzotriazoyl nitroso derivatives are presented. These compounds display unique behavior compared to related nitroso compounds bearing a geminal electron withdrawing group. An unexpected, spontaneous oxidation to the nitro analog was observed in solution and verified through experimental characterization and computational rationale. Kinetic measurements on the conversion of the C-nitroso moiety to the C-nitro in the product are the major features of this work.
General Note: In the series University of Florida Digital Collections.
General Note: Includes vita.
Bibliography: Includes bibliographical references.
Source of Description: Description based on online resource; title from PDF title page.
Source of Description: This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility: by Judit Kovacs.
Thesis: Thesis (Ph.D.)--University of Florida, 2012.
Local: Adviser: Katritzky, Alan R.

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2012
System ID: UFE0044867:00001

Permanent Link: http://ufdc.ufl.edu/UFE0044867/00001

Material Information

Title: New Ventures in Heterocyclic Chemistry
Physical Description: 1 online resource (138 p.)
Language: english
Creator: Kovacs, Judit
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2012

Subjects

Subjects / Keywords: benzotriazole -- dyes -- macrocycles -- nitroso
Chemistry -- Dissertations, Academic -- UF
Genre: Chemistry thesis, Ph.D.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: This thesis describes the synthesis of small molecular libraries of potentially biologically important molecules utilizing standard benzotriazole methodology and also the synthesis of heterocycles for use in material sciences. The aim of the project described in Chapter 2 was the development of a methodology allowing for the synthesis of a library of dye-labeled nucleosides without the use of protecting groups. N-(4-Arylazobenzoyl)-1H-benzotriazoles were prepared in 79-86%yield. Dye-labeled nucleosides were obtained in 30–79% yields by treating N-(4-arylazobenzoyl)-1H-benzotriazoles with appropriate nucleosides. Similarly, N-(4-arylazobenzoyl)-1H-benzotriazoles afforded dye-labeled threoninol conjugates in 55–89% yields. All novel products were characterized by NMR and elemental analysis. Chapter 3 details the synthesis of amino acid conjugates of quinolone antibiotics. The moderate reactivity of acyl benzotriazoles compared to acyl chlorides allows for synthesis without the use of protecting groups.Coupling free amino acids with the benzotriazolides of nalidixic acid, oxolinic acid, cinoxacin, and flumequine was achieved in 43-86%yields. Chapter 4 describes results obtained towards the synthesis of unsymmetrical diketopyrrolopyrrole dyes. The reaction between bis(imidoyl)chloride and substituted ethyl 2-phenylacetate gave the symmetrica ldye, but bis(imidoyl)benzotriazole  was found to be unreactive probably due to steric hindrance. Bis(imidoyl)imidazole however, was found to be a promising candidate for the ultimate synthesis o funsymmetrical dyes. Chapter 5 describes progress towards the synthesis of quinoxalino ligands which potentially may be used as metal scavengers in the purification of metal-catalyzed reactions. The incorporation of various substituted quinoxalines into tetraazamacrocyclic structures, using a metal-free synthetic protocol, should allow synthesis of useful compounds withcomparable or superior properties. Despite being an incomplete work, it of fersa prospective route towards an efficient synthesis of aza-crown macrocycles. In Chapter 6 a new class of geminally-substituted nitroso compounds, i.e. a-benzotriazoyl nitroso derivatives are presented. These compounds display unique behavior compared to related nitroso compounds bearing a geminal electron withdrawing group. An unexpected, spontaneous oxidation to the nitro analog was observed in solution and verified through experimental characterization and computational rationale. Kinetic measurements on the conversion of the C-nitroso moiety to the C-nitro in the product are the major features of this work.
General Note: In the series University of Florida Digital Collections.
General Note: Includes vita.
Bibliography: Includes bibliographical references.
Source of Description: Description based on online resource; title from PDF title page.
Source of Description: This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility: by Judit Kovacs.
Thesis: Thesis (Ph.D.)--University of Florida, 2012.
Local: Adviser: Katritzky, Alan R.

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2012
System ID: UFE0044867:00001


This item has the following downloads:


Full Text

PAGE 1

1 NEW VENTURES IN HETEROCYCLIC CHEMISTRY By JUDIT KOVACS A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVE RSITY OF FLORIDA 2012

PAGE 2

2 2012 Judit Kovacs

PAGE 3

3 To my father, Dr. Peter Kovacs For his continued love and support

PAGE 4

4 ACKNOWLEDGMENTS I would like to thank my advisor, Prof. Alan R. Katritzky for the opportunity, great understanding, and support dur ing this period. I would like to thank my committee members, Prof. Lisa McElwee White, Dr. Steven Miller, Dr. Ion Ghiviriga, and Dr. William R. Kem for their help and support. I would like to thank the University of Florida C hemistry D epartment; special t hanks go to Dr. Ben Smith, Ms Lori Clark, Dr. Tammy Davidson, Ms. Elisabeth Sheppard, Ms. Yaketerina Kovalenko, and Ms. Gwen McCann. I thank c urrent and former group members, especially Dr. Daniebelle N. Haa se, Dr. Megumi Yoshioka Tarver, and Dr. Longchua n Huang for their welcoming spirit their comforting friendship and all of their help in every aspect of my life. Dr. Claudia El Nachef, you have been a best friend and a great support. Dr. Jean Christophe Monbaliu, you have been a guide and support in my last year. Dr. Lucas K. Beagle, thank you for your friendship, your support and encouragement during the last two years. Dr. C. Dennis Hall, thank you for your guidance and constructive criticism I would like to thank the exceptional undergraduates, Ms. Kathryn D. Chinn, Ms. Rachel Wypych, and Mr. Michael DesRosiers for their hard work and friendship. I also thank to my father Dr. Peter Kovacs, my stepmother Dr. Agota Kovacsne Hovany and my family and friends for their support. I would like to give thank s to my loving boyfriend Nicholas Borrero who supported and helped me. Your love and encouragement got me through the most difficult times. It has been an honor and privilege to learn and teach at the University of Florida.

PAGE 5

5 TABLE OF CONTENTS page ACKNOWLEDGMENTS ................................ ................................ ................................ .. 4 LIST OF TABLES ................................ ................................ ................................ ............ 8 LIST OF FIGURES ................................ ................................ ................................ ........ 10 LIST OF SCHEMES ................................ ................................ ................................ ...... 13 LIST OF ABBREVIATIONS ................................ ................................ ........................... 15 ABSTRACT ................................ ................................ ................................ ................... 20 CHAPTER 1 INTRODUCTION ................................ ................................ ................................ .... 22 2 DYE LABELING OF NUCLEOSIDES 1 ................................ ................................ .... 25 2.1 Literature Overview ................................ ................................ ........................... 25 2.2 Results and Discussion ................................ ................................ ..................... 28 2.2.1 Preparation of the Dye Moieties ................................ .............................. 28 2.2.2 Coupling of the A mino Group to Form Dye Labeled Nucleosides ........... 28 2.2.3 Hydroxy Group Coupling to Form Dye Labeled Nucleoside .................... 30 2.2.4 Preparation o f Dye Labeled Threoninol Conjugates ................................ 32 2.3 Conclusion ................................ ................................ ................................ ........ 33 2.4 Experimental Section ................................ ................................ ........................ 33 2.4.1 General Methods ................................ ................................ ..................... 33 2.4.2 General Procedure for the Preparation of 2.10 17 ................................ .. 33 2.4.3 General Procedure for the Preparation of 2.18, 2.22 28 .......................... 37 2.4.4 General Procedure for the Preparation of 2.31 34 ................................ .. 40 3 SYNTHESIS OF AMINO ACID DERI VATIVES OF QUINOLONE ANTIBIOTICS 1 .. 42 3.1 Literature Overview ................................ ................................ ........................... 42 3.2 Results and Discussion ................................ ................................ ..................... 45 3.2.1 Preparation of the Benzotriazole Activated Quinolone Antibiotics ........... 45 3.2.2 Preparation of Nalidixic Amino Acid Conjugates ................................ ..... 46 3.2.3 Preparation of Oxolinic Amino Acid Conjugates ................................ ...... 46 3.2.4 Preparation of Cinoxacin and Flumequine Amino Acid Conjugates ....... 47 3.3 Conclusion ................................ ................................ ................................ ........ 49 3.4 Experimental Section ................................ ................................ ........................ 49 3.4.1 General Methods ................................ ................................ ..................... 49 3.4.2 General Procedure for the Preparation of 3.5 8 ................................ ...... 49 3.4.3 General Procedure for Nalidixic Amino Acid Conjugates ( 3.16 22 ) ......... 51

PAGE 6

6 3.4.4 General Procedure for Oxolinic Amino Acid Conjugates ( 3.25 33 ) ......... 53 3.4.5 General Procedure for Cinoxacin Amino Acid Conjugates ( 3.34 36 ) ...... 57 3.4.6 General Procedure for Flumequine Amino Acid Conjugates ( 3.37 38 ) .... 58 4 SYNTHESIS OF NOVEL UNSYMMETRICAL PYRROLO[3,2 B]PYRROLE 2,5 D IONES ................................ ................................ ................................ .................. 60 4.1 Literature Overview ................................ ................................ ........................... 60 4.1.1 Optical Properties ................................ ................................ .................... 60 4.1.2 Synthesis of Symmetrical Pyrrolo[3,2 b ]pyrrole 2,5 diones ..................... 62 4.1.3 Synthesis of Unsymmetrical Pyrrolo[3,2 b ]pyrrole 2,5 diones ................. 63 4.1.4 Synthesis of Bis(imino)Benzotriazole ................................ ...................... 65 4.2 Results and Discussion ................................ ................................ ..................... 66 4.2.1 Preliminary Investigation of the Photo physical Properties ....................... 66 4.2.2 Synthetic Investigations ................................ ................................ ........... 67 4.3 Conclusion ................................ ................................ ................................ ........ 72 4.4 Experimental Section ................................ ................................ ........................ 72 4.4.1 General Methods ................................ ................................ ..................... 72 4.4.2 Preparation of (N,N'Z,N,N'Z) N,N' (1,2 bis(1H benzo[d][1,2 ,3]triazol 1 yl)ethane 1,2 diylidene)dianiline ( 4.26 ) ................................ ......................... 72 4.4.3 Preparation of (N,N',N,N') N,N' (1,2 di(1H imidazol 1 yl)ethane 1,2 diylidene)dianiline ( 4.27 ) ................................ ................................ ............... 73 4.4.4 Preparation of ethyl 2 (1H imidazol 1 yl) N phenyl 2 (phenylimino) acetimidate ( 4.29 ) ................................ ................................ ......................... 73 4.4.5 Preparation of dimethyl N' 1 ,N' 2 diphenyloxalimidate ................................ 74 5 SYNTHESIS AND APPLICATIONS OF BIS(QUINOXALINO) LIGAND .................. 75 5.1 Literature Overview ................................ ................................ ........................... 75 5.1.1 Quinoxaline: Application and Synthesis ................................ ................... 75 5.1.2 Application and Synthesis of Peraza Crown Macrocycles ....................... 77 5.2 Results and Discussion ................................ ................................ ..................... 79 5.3 Conclusion ................................ ................................ ................................ ........ 84 5.4 Experimental Section ................................ ................................ ........................ 84 5.4.1 General Methods ................................ ................................ ..................... 84 5.4.2 General Procedure for Compounds 5.34 38 ................................ ............ 85 5.4.3 General Procedure for the Preparat ion of Compound 5.39 43 ................ 86 5.4.4 General Procedure for the Preparation of Compound 5.44 48 ................ 87 5.4.5 General Procedure for the Pr eparation of Compound 5.49 55 ................ 87 6 BENZOTRIAZOYL NITROSO DERIVATIVES 1 ............ 88 6.1 Background ................................ ................................ ................................ ....... 88 Benzotriazoyl Nitroso Derivatives ................................ 92 Benzotriazoyl Nitroso Derivatives ................................ ... 94 6.2 Results and Discussion ................................ ................................ ..................... 95 Benzotriazoyl Nitroso Derivatives ................................ .... 95

PAGE 7

7 6. 2.2 Kinetic and Mechanistic Investigations ................................ .................... 98 6.3 Conclusion ................................ ................................ ................................ ...... 100 6.4 Experimental Section ................................ ................................ ...................... 101 6.4.1 General Methods ................................ ................................ ................... 101 6.4.2 Synthesis of Nitroso Compounds 6.27 32 ................................ ............ 102 6.4.3 X ray Data for 6 .27 and 6.42 ................................ ................................ 103 6.4.4 Kinetic Data ................................ ................................ ........................... 104 7 SUMMARY OF ACHIEVEMENTS ................................ ................................ ........ 123 LIST OF REFERENCES ................................ ................................ ............................. 125 BIOGRAPHICAL SKETCH ................................ ................................ .......................... 138

PAGE 8

8 LIST OF TABLES Table page 2 1 Yi elds for N acylated dye labeled nucleosides 2.10 17 ................................ ...... 29 2 2 O acylated dye labeled nucleosides 2.22 27 ................................ ... 31 2 3 Yields for the dye labeled threoninol conjugates ( 2.31 34 ) ................................ 33 3 1 Preparation of acid benzotriazolides ( 3.5 8 ) ................................ ....................... 45 3 2 Preparation of n alidixic amino acid conjugates 3.16 22 ................................ ..... 46 3 3 Preparation of oxolinic amino acid conjugates 3.25 33 ................................ ...... 47 3 4 Preparation of cinoxa cin amino acid conjugates 3.34 36 ................................ ... 48 3 5 Preparation of flumequine amino acid conjugates 3.37 38 ................................ 48 4 1 Optical properties of th e symmetrically substituted pyrrolo[3,2 b ]pyrrole 2,5 diones ( 4.3 ) [00JOC729] ................................ ................................ .................... 61 4 2 Optical properties of the asymmetrically substituted pyrrolo[3,2 b ]pyrrole 2,5 diones ( 4.4 ) [06S2507] ................................ ................................ ....................... 62 4 3 Computed max values for a representative series of pyrrolo[3,2 b ]pyrrole 2,5 diones ................................ ................................ ................................ ................. 67 4 4 Reaction conditions for benzotriaz ole derivative ( 4.26 ) ................................ ...... 68 4 5 Reaction conditions for the imidazole derivative ( 4.27 ) ................................ ...... 71 5 1 Synthesis of quinoxalinones 5.23 26 ................................ ................................ .. 80 5 2 Synthesis of 2,3 dichloroquinoxalines 5.27 30 ................................ ................... 80 5 3 Yields for intermediates 5.34 38 ................................ ................................ ......... 81 5 4 Synthesis of intermediates 5.39 43 ................................ ................................ .... 82 5 5 Cyclization conditions for the formation of macrocycle ( 5.49 55 ) ........................ 84 6 1 benzotriazoyl nitroso compounds 6.27 32 ................................ 93 6 2 Isodesmic reactions for radical exchange on different cyclohexyl substrates and corresponding radical stabilization energy (RSE) ................................ ........ 97

PAGE 9

9 6 3 Homolytic bond dissociation energies (BDE) for compounds 6.19 6.27 and 6.41 ................................ ................................ ................................ .................... 97 6 4 Heterolytic bond dissociation energie s (BDE) for compounds 6.27 6.15 and 6.41 ................................ ................................ ................................ .................... 98 6 5 Data for the determination of the extinction coefficient in methanol .................. 105 6 6 Da ta for the determination of the rate constant (k obs ) and half life in methanol 105 6 7 Data for the determination of the extinction coefficient in dichloromethane ...... 107 6 8 Data for the determination of the rate constant (k obs ) and half life in dichloromethane ................................ ................................ ............................... 108 6 9 Data for the determination of the extinction coeffici ent in acetonitrile ............... 109 6 10 Data for the determination of the rate constant (k obs ) and half life in acetonitrile ................................ ................................ ................................ ........ 110 6 1 1 Data for the determination of the extinction coefficient in acetonitrile:water 7:3 112 6 12 Data for the determination of the rate constant (k obs ) and half life in acetonitrile:water 7:3 ................................ ................................ ........................ 112 6 13 Data for the determination of the extinction coefficient in acetonitrile ............... 114 6 14 Data for the determination of the half life in acetonitrile at 1mg/mL concentration ................................ ................................ ................................ .... 115 6 15 Data for the determination of the half life in acetonitrile at 2 mg/mL concentration ................................ ................................ ................................ .... 116 6 16 Data for the determination of the half life in acetonitrile at 4 mg/mL concentration ................................ ................................ ................................ .... 117 6 17 Data for the determination of the extinction coefficient for 4.31 in dichloromethane ................................ ................................ ............................... 119 6 18 Data for the determination of the half life for 4.31 in dichloromethane .............. 120 6 19 Data for the determination of the extin ction coefficient for 4.32 in dichloromethane ................................ ................................ ............................... 121 6 20 Data for the determination of the half life for 4.32 in dichloromethane .............. 121

PAGE 10

10 LIST OF FIGURES Figure pag e 1 1 Tautomerization of 1 H and 2 H benzotriazole ................................ .................... 22 1 2 Different roles of benzotriazole ................................ ................................ ........... 23 1 3 Synthesis of acyl benzotriazolides ................................ ................................ ...... 24 2 1 ( E )/( Z ) isomerization of azobenzene ................................ ................................ ... 26 2 2 N ames and numbering of nucleobases and nucleosides ................................ ... 27 3 1 Selected first generation quinolone antibiotics ................................ ................... 43 3 2 Literature prepa ration of quinolone amino acid ester conjugates ....................... 44 4 1 Most commonly used DPP pigment skeletons ................................ .................... 60 4 2 One pot synthesis of symm etrical pyrrolo[3,2 b [pyrrole 2,5 diones ( 4.3 ) ........... 63 4 3 Preparation of bis(imidoyl)chlorides ( 4.5 ) ................................ ........................... 63 4 4 Synthesis of pyrrolo[3,2 b ]pyrrole 2,5 diones ( 4.4 ) with different substituents at the nitrogen atoms ................................ ................................ .......................... 64 4 5 Synthesis of asymmetrical pyrrolo[3,2 b ]pyrrole 2,5 diones ( 4.19 ) ..................... 65 4 6 Synthesis of bis(imidoyl)benzotriazole ( 4.22 ) ................................ ..................... 66 4 7 Substitution of the benzotriazole in a stepwise fashion ................................ ...... 68 4 8 Computed structures for 4.25 27 ................................ ................................ ........ 69 5 1 General structure of the bis(quinoxalino) ligand ................................ ................. 75 5 2 Selected quinox aline natural products ................................ ................................ 76 5 3 Selected preparations of quinoxalines ................................ ................................ 77 5 4 Selected examples of peraza crown macrocycles ................................ .............. 78 5 5 crown macrocycles ................................ ........... 78 6 1 Three step process for the formation of 1,2 oxazines in nitroso hetero Diels leaving group nitroso 6.1 ................................ ............... 89

PAGE 11

11 6 2 Most frequently reported HNO donors. HNO/NO selectivity depends mainly on pH, concentration and medium polarity. ................................ ........................ 91 6 3 acetoxy nitroso compounds ................................ .......... 92 6 4 cyano nitroso compound 6.19 ............................. 92 6 5 Aromatic substrate 6.33 benzotriazoyl nitroso 6.34 ................................ ................................ ................................ ........ 93 6 6 benzotriazoyl nitroso derived from methyl ketoxi me 6.35 ............................... 93 6 7 X ray structure of monomer 6.27 ................................ ................................ ....... 94 6 8 Picture of the TSs associated with the cycloaddition of the selected nit roso compounds with butadiene. ................................ ................................ ................ 96 6 9 Half life of 6.27 as measured in various solvents. ................................ .............. 99 6 10 Kinetics for dissociation at va rious concentrations of 6.27 .............................. 100 6 11 Comparison of the half life of 6.27 and 6.31 32 ................................ ............... 100 6 12 Concentration versus absorbance plot for the calculation of the extinction coefficient in methanol ................................ ................................ ...................... 105 6 13 Time versus normalized concentration plot for the calculation of the half live in methanol ................................ ................................ ................................ ....... 106 6 14 Time versus ln(c) plot for the calculation of the rate constant (k obs ) in methanol ................................ ................................ ................................ ........... 107 6 15 Concentration versus absorbance plot for the calcul ation of the extinction coefficient in dichloromethane ................................ ................................ .......... 107 6 16 Time versus normalized concentration plot for the calculation of the half live in dichloromethane ................................ ................................ ........................... 109 6 17 Time versus ln(c) plot for the calculation of the rate constant (k obs ) in dichloromethane ................................ ................................ ............................... 109 6 18 Concentration versus absorbance plot for the calcu lation of the extinction coefficient in acetonitrile ................................ ................................ ................... 110 6 19 Time versus normalized concentration plot for the calculation of the half live in acetonitrile ................................ ................................ ................................ .... 111 6 20 Time versus ln(c) plot for the calculation of the rate constant (k obs ) in acetonitrile ................................ ................................ ................................ ........ 111

PAGE 12

12 6 21 Concentration versus absorbance plot for the calculation o f the extinction coefficient in acetonitrile:water 7:3 ................................ ................................ .... 112 6 22 Time versus normalized concentration plot for the calculation of the half live in acetonitrile:water 7:3 ................................ ................................ ..................... 113 6 23 Time versus ln(c) plot for the calculation of the rate constant (k obs ) in acetonitrile:water 7:3 ................................ ................................ ........................ 114 6 24 Concentration versus absorbance plot for the calculation of the extinction coefficient in acetonitrile ................................ ................................ ................... 114 6 25 Time versus normalized concentration plot for the calculation of the half live in acetonitrile at 1 mg/mL concentrat ion ................................ ........................... 116 6 26 Time versus normalized concentration plot for the calculation of the half live in acetonitrile at 2 mg/mL concentration ................................ ........................... 117 6 27 Time versus normalized concentration plot for the calculation of the half live in acetonitrile at 4 mg/mL concentration ................................ ........................... 119 6 28 Concentration versus absorbance plot for the calc ulation of the extinction coefficient for 4.31 in dichloromethane ................................ ............................. 119 6 29 Time versus normalized concentration plot for the calculation of the half live for 4.31 in dichloromethane ................................ ................................ .............. 120 6 30 Concentration versus absorbance plot for the calculation of the extinction coefficient for 4.32 in dichloromethane ................................ ............................. 121 6 31 Time versus normalized concentration plot for the calculation of the half live for 4.32 in dichloromethane ................................ ................................ .............. 122

PAGE 13

13 LIST OF SCHEMES Scheme page 2 1 Preparation of the azodyes 2.4 5 ................................ ................................ ........ 28 2 2 Preparation of dye labeled nucleosides 2.10 17 ................................ ................. 29 2 3 Formation of the doubly a cylated product 2.18 ................................ ................... 30 2 4 Preparation of dye labeled nucleosides 2.22 27 ................................ ................. 31 2 5 Dye labeling of thymidine ( 2.20 ) ................................ ................................ ......... 32 2 6 Dye labeling of threoninol ................................ ................................ ................... 32 3 1 Preparation of benzotriazole activated quinolone antibiotics .............................. 45 3 2 Preparation of nalidixic acid amino acid conjugates 3.16 22 .............................. 46 3 3 Preparation of oxolinic acid amino acid conjugates 3.25 33 ............................... 47 3 4 Preparation of cinoxacin amino acid conjugates 3.34 36 ................................ ... 48 3 5 Preparation of flumequine amino acid conjugates 3.37 38 ................................ 48 4 1 Synthesis of compound bis(imidoyl)benzotriazole 4.26 ................................ ...... 68 4 2 Synthesis of compound bis(imidoyl)imidazole 4.27 ................................ ............ 70 4 3 Formation of the side product 4.29 from bis(imidoyl)imidazole ( 4.27 ) ................ 70 5 1 Synthesis of quinoxalinones 5.23 26 ................................ ................................ .. 79 5 2 Synthesis of 2,3 dichloroquinoxalines 5.27 30 ................................ ................... 80 5 3 Synthesis of intermediates 5.34 38 ................................ ................................ .... 81 5 4 Synthesis of interme diates 5.39 43 ................................ ................................ .... 81 5 5 Boc deprotection to give sulfate salts 5.44 48 ................................ .................... 82 5 6 Synthesis of macrocycles 5.49 55 ................................ ................................ ...... 83 5 7 Synthesis of macrocycle Cs + complex 5.56 ................................ ........................ 83 5 8 Synthesis of macrocycles 5.50 51 ................................ ................................ ...... 83 6 1 Comparison of the reactivities of nitroso compounds ................................ ......... 96

PAGE 14

14 6 2 Release of NO and formation of compound 6.42 from compound 6.27 .............. 98

PAGE 15

15 LIST OF ABBREVIATION S AA Amino acid AcOH Acetic acid Ac 2 O Acetic anhydride Anal. Analytical aq. Aqueous Ala A lanine BtH 1 H benzotriazole Bi Bismuth Boc tert Butoxycarbonyl BuLi n Butyllithium B n NH 2 Benzylamine C Celsius degree Calcd. Calculated CDCl 3 Deuterated chloroform CM L Chronic myeloid leukaemia Cu Copper Chemical shift d Doublet d Day dd Doublet of doublet DABCYL 4 [4 Dimethylaminoohenylazo]benzoic acid DBU 1,8 Diazabicyclo[5.4.0]undec 7 ene DCM Methylene chloride DFT Density functional theory

PAGE 16

16 DMAP Dimethylaminopyrid ine DMF Dimethylformamide DMSO d 6 Deuterated dimethyl sulfoxide DNA Deoxyribonucleic acid DPP Diketopyrrolopyrrole EDG Electron donating group e.g. Exempli gratia Et Ethyl et a l. And others Et 3 N Triethylamine EtOH Ethanol Eq. Equivalent eV Electron volt EW G Electron withdrawing group FRET Fluorescence resonance energy transfer g Gram Gly Glycine h Hour i. e. id est HBr Hydrobromic acid HCl Hydrochloric acid HIV Human immunodeficiency virus HNO 3 Nitric acid HOMO Highest occupied molecular orbital HPLC High p erformance liquid chromatography

PAGE 17

17 H 2 SO 4 Sulfuric acid Hz Hertz IR Infra red J Coupling constant K 2 CO 3 Potassium carbonate KOAc Potassium acetate KOH Potassium hydroxide KOtBu Potassium tert butoxide Absorption wavelength L Levorotary LDA Lithium diisopr opylamide LED Light emitting diode Leu Leucine LiHMDS Lithium bis(trimethylsilyl)amide LUMO Lowest unoccupied molecular orbital M Mic romolar m Multiplet Me Methyl MeCN Acetonitrile MeI Methyl iodide Me 2 NH Dimethylamine MeOH Methanol Met Methionine min Min ute mL Milliliter

PAGE 18

18 mmol Millimole Mn Manganese mp Melting point MW Microwave N Normal NaOEt Sodium ethoxide NaOH Sodium hydroxide NaOMe Sodium methoxide nm Nanometer NMR Nuclear magnetic resonance N.R. No reaction Global electrophilicity index OLED Organic light emitting diode o/n overnight p Para PCR polymerase chain reaction Pd Palladium Ph Phenyl Phe Phenylalanine PhH Benzene PhMe Toluene PhOH Phenol Py. Pyridine q Quartet RNA Ribonucleic acid

PAGE 19

19 rt Room temperatu re Ru Ruthenium s Singlet SOCl 2 Thionyl chloride t Triplet tBuOH tert Butanol TEA Triethylamine TfOH Trifluoromethanesulfonic acid THF Tetrahydrofuran Trp Tryptophan UV Ultra violet TMS Tetramethylsilane TMS Cl Trimethylsilylchloride Val Valine VZV Varicel la zoster virus VIS Visible light W Watt

PAGE 20

20 Abstract of Dissertation Presented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy NEW VENTURES IN HETEROCYC LIC CHEMISTRY By Judit Kovacs December 2012 Chair: Alan R. Katritzky Major: Chemistry This thesis describes the synthesis of small molecular libraries of potentially biologically important molecules utilizing standard benzotriazole methodology and also the synthesis of heterocycles for use in material sciences. The aim of the project described in Chapter 2 was the development of a methodology allowing for the synthesis of a library of dye labeled nucleosides without the use of protecting groups. N (4 A ry lazobenzoyl) 1 H benzotriazoles were prepared in 79 86% yield. Dye labeled nucleosides were obtained in 30 79% yields by treating N (4 arylazobenzoyl) 1 H benzotriazoles with appropriate nucleosides. Similarly, N (4 arylazobenzoyl) 1 H benzotriazoles afforded dye labeled threoninol conjugates in 55 89% yields. All novel products were characterized by NMR and elemental analysis. Chapter 3 details the synthesis of amino acid conjugates of quinolone antibiotics. The moderate reactivity of acyl benzotriazoles comp are d to acyl chlorides allows for synthesis without the use of protecting groups. Coupling free amino acids with the benzotriazolides of nalidixic acid, oxolinic acid, cinoxacin, and flumequine was achieved in 43 86% yield s

PAGE 21

21 Chapter 4 describes results obt ained towards the synthesis of unsymmetric al diketopyrrolopyrrole dyes. The reaction between bis(imidoyl)chloride and substituted ethyl 2 phenylacetate gave the symmetrical dye, but bis(imidoyl)benzotriazole was found to be unreactive probably due to ster ic hindrance Bis(imidoyl)imidazole however, was found to be a promising candidate for the ultimate synthesis of unsymmetrical dyes. Chapter 5 describes progress towards the synthesis of quinoxalino ligands which potentially may be used as metal scavengers in the purification of metal catalyzed reactions. The incorporation of various substituted quinoxalines into tetraazamacrocyclic structures, using a metal free sy nthetic protocol, should allow synthesis of use ful compounds with comparable or superior prop erties. Despite being an incomplete work, it offers a prospective route towards an efficient synthesis of aza crown macrocycles. In Chapter 6 a new class of geminally benzotriazoyl nitroso derivatives are presented. Th ese compounds display unique behavior compared to related nitroso compounds bearing a geminal electron withdrawing group. An unexpected, spontaneous oxidation to the nitro analog was observed in solution and verified through experimental characterization a nd computational rationale. K inetic measurements on the conversion of the C nitroso moiet y to the C nitro in the product are the major features of this work.

PAGE 22

22 CHAPTER 1 INTRODUCTION The work discussed in this thesis is divided into two major areas. In t he first part experiments are described for the synthesis of small potentially biologically active molecular libraries using standard benzotriazole chemistry T he second part describes experiments for the synthesis of heterocycles with interesting propert ies from the point of view of material sciences. Heterocycles are very importan t in organic chemistry and many research programs have been dedicated to their synthesis, structure determination and reactivity. [03 CHC1 ] In particular 1 H benzotriazole plays an important part in this research and some of its properties are described herein. Figure 1 1 Tautomerization of 1 H and 2 H benzotriazole 1 H Benzotriazole ( 1.1 ), consist s of two fused rings: a six membered benzoid ring a n d a five membered triazole ring. It is a stable and inexpensive white solid that [54SCI989] exists in two tautomeric form s. 1 H benzotriazole ( 1.1 ) is predominant in solution and solid phase, while 2 H B enzotriazole ( 1.2 ) is predominant in the gas phase. (F igure 1 1) It behaves as a weak acid (pK a = 1.6) as well as a weak base (pK a = 8.3); thus benzotriazole can be removed from reaction mixtures by a simple acid or base work up during purification.

PAGE 23

23 Figure 1 2 Different rol es of benzotriazole Benzotriazole has the ability to act as a leaving group [94CSR363], a proton activator [98CR409, 06S3231], a cation stabilizer [91CR1809], a radical precursor [04CC2356], and an anion precursor [97JOC4148]. (Figure 1 2a e) The use of be nzotriazole as a leaving group is of the greatest importance to this work. Relative to acyl leaving groups, benzotriazole exhibits a modulated reactivity, which offers an advantage over the more reactive acyl halides and acyl tosylates.[91T268 ] Synthesis of acyl benzotriazolide 1.4 occurs under mild conditions starting from ac id chlorides or carboxylic acids (Figure 1 3). Formation from the carboxylic acid 1.5 involves in situ generation of thionyl benzotriazole (from an excess of 1 H benzotriazole and thio nyl chloride) or the reaction with benzotriazole mesylate and triethylamine.

PAGE 24

24 [00JOC8210, 03S2795, 92T7817] While the thionyl chloride method is widely utilized, it cannot be used when the substrate (i.e Boc protected amino acids) is acid sensitive due to t he in situ formation of hydrochloric acid. Figure 1 3. Synthesis of acyl benzotriazolides Benzotriazole mediated acylation has been shown to be effective for C O N and S nucleophiles. [03JOC4932, 03JOC5720, 05S 165 6, 00S2029] The unique reactivity and stabilization effect of benzotriazole allow these transformations to occur under mild conditions and often in high yields compared to literature methods. [96JOC1624, 00JOC82 1 0, 06S411] The use of acyl benzotriazoles a s acylating reagents is discussed in Chapter s 2 and 3, which allow s the synthesis of b iologically important molecules. The second part of this work focuses on the development of new materials wi th interesting physicochemical properties. The goal in Chapter 4 is the synthesis of new dye moieties. Taking advantage of the moderate reactivity of bis(imidoyl)benzotriazole compare to bis(imidoyl)chloride, allow s the of selectivity leading to a new class of dyes with red shifted colors. In the last chapter, the de velopment of a new class of chelating an agent is described.

PAGE 25

25 CHAPTER 2 DYE LABELING OF NUCLEOSI DES 1 2.1 Literature Overview Labeled nucleosides and nucleotides are of great interest in bio and medicinal chemistry due to the possibility of incorporation into nucleic acid s facilitating determination of the gene structure. T hey are also used for monitoring enzymatic reactions, structural or functional analysis, and locating complementary sequences for hybridization probes. [91EMB57] Common ly used labels i nclude 31 P, 15 N, and 14 C, due to their sensitivity, but disadvantages include handling and disposing of hazardous material, short half lives, and limited stability [91EMB57, 95MCP145, 07US072196] thus encouraging a search for alternatives. A variety of no n isotopic labeling methods have been developed, including the use of fluorescent tags [91EMB57, 95MCP145, 98BBA178], enzyme labeling [91EMB57, 95MCP145, 98BBA178, 01CC1002], and incorpor ation of reporter molecules, e.g biotin, avidin or streptavidin [91E MB57, 89NAR7643]. Recently, dye labeling with azobenzene derivatives ha s been reported with biologically relevant products, such as antibodies [00WO027813], DNA probes [03TL8571], lipids [06OL2023], cytokines [00 WO027813], cells [08CR1588], polymers [93B C105, 96BC356], and monolayers [80JACS2167, 80JACS2176]. Dye labeling has also enabled the isolation and detection of biologically active molecules, like amino acids [02JACS9674, 06JACS15596, 06OL2575, 02OL737, 03OL2445]. The azobenzene derivatives undergo conformational changes through ( E )/( Z ) 1 Reproduced with permission from Chemical Biology & Drug Design 2009 396. Copyright 2009 John Wiley and Sons

PAGE 26

26 isomerization [00S1624, 05CR1377, 06N512, 04OL2595], allowing simple detection and use as photoregu lators. [96TL637, 98TL9015] (Figure 2 1) Figure 2 1 ( E )/( Z ) isomerization of azobenzene Base modified nucleosides have found application as antiviral tools against VZV and HIV, in the evaluation and study of DNA damage, and the anti sense approach to DNA probes with fluorescent properties [99JMC4479, 00BMCL1215, 00JOC2959, 00EJOC211, 00OL227]. DABCYL (4 [4 D imethylaminophenylazo]benzoic acid) is a non fluorescent dye used to quench Real Time PCR (polymerase chain reaction ) probes, i.e. molecular beacons [96NB303] and double labeled probes [96JME23]. When DABCYL is coupled to an oligonucleotide in close proximity to a fluorophore, it absorbs the e mitted light of the fluorophore. I ncreasing the distance (i.e. by enzymatic cl eavage of the oligonucleotide or change of a beacon) excites the fluorophore and the emission signal can be detected [96NB303]. The strong absorption of DABCYL in the visible range can be used for visual detection and colorimetric probes of oligonucleotide s. Nucleosides can be modified at the 3 or 5 positions, or at the nucleobases. If the modification is an attachment at the 5 position of the nucleosides, polymerase chain reaction (PCR) applications are possible. M position usuall y prevent further enzymatic reactions [91EMB57]. Gunnlaugsson et al coupled DABCYL, one of the most frequently used FRET (Fluorescence Resonance Energy Transfer ) quenchers, covalently to thymidine phosphoramidites as esters at position 3 O and 5 O of t he deoxyribose unit of a thymidine nucleoside [03TL8571]. These azo dye labeled

PAGE 27

27 nucleotides were incorporated into a 16 mer Chronic Myeloid Leukaemia (CML) antisense oligonucleotide at the 5 terminus as a molecular probe for nucleic acids. (Figure 2 2) Figure 2 2 Names and numbering of nucleobases and nucleosides In this project, nucleosides were designed incorporating tethered azo based components expected to undergo reversible cis trans changes in response to visible l ight irradiation. Disadvantages of the literature methods of dye labeling techniques include utilization of complex procedures, harsh reaction conditions, low yields, long reaction times and difficulties associated with product purification [03TL8571, 01AC IE2671]. N Acylbenzotriazoles have proved advantageous for N C and O acylation [05S1656, 08OBC2400, 05ARKIVOC36], and afford an efficient method for chemoselective reactions. T he preparation of azobenzene dye labeled nucleosides 2.10 17, 2.22 27 and dy e labeled t hreoninol conjugates 2.31 34 is reported using N (4 arylazobenzoyl) 1 H benzotriazoles 2.4 5

PAGE 28

28 2.2 Results and Discussion The aim of this project was to develop a methodology that will allow the synthesis of a library of dye labeled nucleosides wi thout the need for protecting groups. 2.2.1 Preparation of the Dye Moieties The azo dye coupling partners were synthesized using standard benzotriazole methodology developed by Katritzky et al [08OBC2400] ( E ) 4 ( P henyldiazenyl)benzoic acid ( 2. 1 ) or ( E ) 4 ((3 (dimethylamino) phenyl)diazenyl)benzoic acid ( 2.2 ) were treated with 1 eq. of 1 (methylsulfonyl) 1 H benzotriazole ( 2.3 ) in the presence of triethylamine and the mixture was heated under reflux to gi ve products 2. 4 5 in 79 86% yields (Scheme 2 1 ). Scheme 2 1 Preparation of the azodyes 2.4 5 2.2.2 Coupling of the Amino Group to Form Dye Labeled Nucleoside s Nucleosides containing a free amino group, such as adenosine ( 2. 6 ), cytidine ( 2. 7 ), deoxyadenosine ( 2. 8 ), and deo xycytidine ( 2. 9 ) were reacted with the benzotriazole activated dye moieties ( 2. 4 5 ) to give the dye labeled nucleosides ( 2.10 17 ) in 30 79% yield (Scheme 2 2, Table 2 1) The acylation reaction was chemoselective, only the free amino group reacted with the dye benzotriazolides ( 2.4 5 ) and none of the hydroxyl groups.

PAGE 29

29 Scheme 2 2 Preparation of dye labeled nucleosides 2.10 17 Table 2 1 Yields for N acylated dye labeled nucleosides 2.10 17 Reactant R 1 Product Yield (%) ade nosine ( 2. 6 ) H 2. 10 68 adenosine ( 2. 6 ) N ( CH 3 ) 2 2. 12 53 deoxyadenosine ( 2. 8 ) H 2. 11 40 deoxyadenosine ( 2. 8 ) N(CH 3 ) 2 2. 13 50 cytidine ( 2. 7 ) H 2. 14 79 cytidine ( 2. 7 ) N(CH 3 ) 2 2. 16 30 deoxycytidine ( 2. 9 ) H 2. 15 45 deoxycytidine ( 2. 9 ) N(CH 3 ) 2 2. 17 35 A c atalytic amount of 4 dimethylaminopyridine (DMAP) was used in the coupling of adenosine ( 2.6 ) with dye moiety 2.5 in order to accelerate the acyl transfer. Catalysis, h owever, was not observed, but instead a double acylation at N O of adenosine, le ading to 2.18 in 18% yield along with the expected 2.12 in 57% yield (Scheme 2 3) was found

PAGE 30

30 Scheme 2 3 Formation of the doubl y acylated product 2.18 2.2.3 Hydroxy Group Coupling to Form Dye Labeled Nucleoside Nucleoside s that do not possess free amino groups, such as uridine ( 2.19 ), thymidine ( 2. 20 ), and deoxyuridine ( 2. 21 ), were acylated at the hydroxyl groups of the sugar moiety benzotriazole a ctivated azo dye s ( 2.4 5 ) were reacted with the nucleosides in the presence of 0.1 equivalent of DMAP to give dye labeled nucleosides ( 2.22 27 ) in 31 52% yield (Scheme 2 4, Table 2 2).

PAGE 31

31 Scheme 2 4 Preparation of dye label ed nucleosides 2.22 27 Table 2 2 O acylated dye labeled nucleosides 2.22 27 Reactant R 1 Product Yield (%) uridine ( 2. 19 ) H 2.22 52 uridine ( 2. 19 ) N(CH 3 ) 2 2. 24 50 deoxyuridine ( 2. 20 ) H 2. 23 45 deoxyuridine ( 2. 20 ) N(CH 3 ) 2 2. 25 31 thymidine ( 2. 21 ) H 2. 26 54 thymidine ( 2. 21 ) N(CH 3 ) 2 2. 27 50 O O doubly acylated product ( 2.28 ) was also observed in 37% yield when thymidine ( 2.20 ) was coupled with ( E ) (1 H benzo[ d ][1,2,3]triazol 1 yl)(4 (phenyldiazenyl)phenyl) methanone ( 2.4 ) (Scheme 2 5).

PAGE 32

32 Scheme 2 5 Dye labeling of thymidine ( 2.20 ) 2.2.4 Preparation of Dye Labeled Threoninol Conjugates Dye labeled threoninol was incorporated into oligodeoxynucleotides by Komiyama in order to better understand the ph otoregulation during transcription [01ACIE2671]. Thus, acylation was carried out selectively on the amino group of L or D threoninol under similar conditions as the benzotriazole activated azo dyes ( 2.4 5 ) giving the corresponding conjugates ( 2.31 34 ) in 55 89% yield (Scheme 2 6, Table 2 3). Scheme 2 6 Dye labeling of threoninol

PAGE 33

33 Table 2 3 Yields for the dye labeled threoninol conjugates ( 2.31 34 ) Reactant R 1 Product Yield (%) D threoninol ( 2. 29 ) H 2.31 60 D threonino l ( 2. 29 ) N(CH 3 ) 2 2. 32 65 L threoninol ( 2. 30 ) H 2. 33 55 L threoninol ( 2. 30 ) N(CH 3 ) 2 2. 34 89 2.3 Conclusion In summary, the convenient preparation of dye labeled nucleosides incorporating azobenzene dyes has been developed, utilizing N (4 arylazobenzoyl) 1 H benzotriazoles ( 2.4 5 ) under mild reaction conditions. 2.4 Experimental Section 2.4.1 General Methods Melting points were determined on a capillary point apparatus equipped with a digital thermometer. NMR spectra were recorded in DMSO d 6 with TMS as an internal standard for 1 H (300 MHz or 500 MHz) or solvent as an internal standard for 13 C (75 MHz or 125 MHz). Elemental analyses were performed on a CarloErba 1106 instrument. All reactions were performed using commercially available nucleoside substrates solvents, and reagents without inert gas protection 2.4.2 General Procedu re for the P reparation of 2.10 17 Equimolar quantities of N (4 arylazobenzoyl) 1 H benzotriazole (1 mmol) and the appropriate nucleoside (1 mmol) in DMF (5 mL) were stirred at room temperature for 24 h. After addition of dichloromethane/hexanes (2 mL/10 mL) the precipitate was filtered and purified by flash column chromatography on silica gel (CH 2 Cl 2 : MeOH, 9:1 ) to give the corresponding dye labeled nucleoside. N (9 ((2 R ,3 R ,4 S ,5 R ) 3,4 Dihydroxy 5 (hydroxymethyl)tetrahydrofuran 2 yl) 9 H purin 6 yl) 4 (( E ) phenyldiazenyl)benzamide (2.10) : Red microcrystals (68%), mp

PAGE 34

34 215 217C, 1 H NMR (DMSO d 6 proton signals of exchangeable hydrogen atoms are 3.82 (m, 2H), 4.37 (s, 1H), 5.02 5.08 (m, 1H), 5.59 (d, J = 5.1Hz, 1H ), 5.75 5.81 (m, 1H), 5.98 (d, J = 6.3 Hz, 1H), 6.06 (d, J = 7.3 Hz, 1H), 7.43 (br s, 2H), 7.90 8.00 (m, 2H), 8. 03 8.06 (m, 2H), 8.17 (d, J = 2.1 Hz, 1H), 8.28 8.32 (m, 2H), 8.44 8.43 (m, 1H). 13 C NMR (DMSO d 6 122.9, 129.6, 130.9, 131.6, 132.4, 140.0, 149.1, 151.9, 152.5, 154.6, 156.3, 164.5. Anal. Calcd for C 23 H 21 N 5 O 7 : C, 58.10; H, 4.45; N, 20.62. Found: C, 57.82; H, 4.26; N, 20.24. N (9 ((2 R ,4 S ,5 R ) 4 Hydroxy 5 (hydroxymethyl)tetrahydrofuran 2 yl) 9 H purin 6 yl) 4 (( E ) phenyldiazenyl)benzamide (2.11): Orange microcrystals (40%), mp 205 206C, 1 H NMR (DMSO d 6 2.38 2.44 (m, 1H), 2.95 2.99 (m, 1H), 4.16 4.18 (m, 1H), 4.44 4.50 (m, 1H), 4.58 4.69 (m, 2H), 5.59 (d, J = 4.3 Hz, 1H), 6.38 6.42 (t, J = 6.3 Hz, 1H), 7.31 (br s, 2H), 7.61 7.63 (m, 2H), 7.93 7.98 (m, 4H), 8.10 8.14 (m, 3H), 8.32 (d, J = 2.9 Hz, 1H). 13 C NMR (DMSO d 6 130.7, 131.4, 132.4, 139.7, 149.1, 151.9, 152.6, 154.5, 156.1, 165.0. Anal. Calcd for C 23 H 21 N 7 O 4 : C, 60.12; H, 4.61; N, 21.34. Found: C, 59.91; H, 4.68; N, 21.05. N (9 ((2 R ,3 R ,4 S ,5 R ) 3,4 D ihydroxy 5 ( hydroxymethyl)tetrahydrofuran 2 yl) 9 H purin 6 yl) 4 (( E ) (4 (dimethylamino)phenyl)diazenyl)benzamide (2.1 2 ): Red microcrystals (53%), mp 262 264C, 1 H NMR (DMSO d 6 3.82 (m, 2H), 4.36 (br s, 1H), 5.04 (q, J = 6.3 Hz, 1H), 5.54 5.58 (m, 1H), 5.74 5.81 (m, 1H), 5.97 (d, J = 6.2 Hz, 1H), 6.06 (d, J = 7.1 Hz, 1H), 6.86 (d, J = 9.2 Hz, 2H), 7.44 (br s, 2H), 7.86 (d, J = 8.9 Hz, 2H), 7.91 (d, J = 8.5 Hz, 2H), 8.16 8.24 (m, 2 H), 8.43 (s, 1H). 13 C NMR (DMSO d 6 .7, 87.8, 111.6, 119.4, 121.9, 125.4,

PAGE 35

35 129.5, 130.8, 140.0, 142.7, 149.1, 152.5, 153.1, 155.4, 156.3, 164.7. TOF MS m/z [M + H] + calcd for C 25 H 26 N 8 O 5 : 519.2099; found: 519.2112. N (9 ((2 R ,4 S ,5 R ) 4 Hydroxy 5 (hydroxymethyl)tetrahydrofuran 2 yl) 9 H purin 6 y l) 4 (( E ) (4 (dimethylamino)phenyl)diazenyl)benzamide (2.13): Red microcrystals (50%), mp 221 222C, 1 H NMR (DMSO d 6 2.43 (m, 1H), 2.91 3.00 (m, 1H), 3.08 (s, 6H), 4.13 4.20 (m, 1H), 4.41 4.47 (m, 1H), 4.55 4.61 (m, 1H), 4.64 4.69 (m, 1H), 5.58 (d, J = 4.3 Hz, 1H), 6.39 (t, J = 6.6 Hz, 1H), 6.85 (d, J = 9.2 Hz, 2H), 7.32 (s, 2H), 7.83 (d, J = 8.5 Hz, 4H), 8.05 (d, J = 8.7 Hz, 2H), 8.14 (s, 1H), 8.32 (s, 1H). 13 C NMR (DMSO d 6 130.5, 139.7, 142.7, 149.1, 152.6, 153.1, 155.3, 156.1, 165.2. Anal. Calcd for C 25 H 26 N 8 O 4 : C, 59.75; H, 5.21; N, 22.30. F ound: C, 59.37; H, 5.29; N, 21.92. N (1 ((2 R ,3 R ,4 S ,5 R ) 3,4 Dihydroxy 5 (hydroxymethyl) tetrahydrofuran 2 yl) 2 oxo 1,2 dihydropyrimidin 4 yl) 4 (( E ) phenyldiazenyl)benzamide (2.14): Yellow microcrystals (79%), mp 258 260C, 1 H NMR (DMSO d 6 J = 11.3 Hz, 1H), 3.77 (d, J = 11.7 Hz, 1H), 3.90 4.03 (m, 3H), 5.08 (s, 1H), 5.21 (s, 1H), 5.54 (s, 1H), 5.82 (d, J = 2.5 Hz, 1H), 7.37 (br s, 1H), 7.62 7.64 (m, 3H), 7.93 8.10 (m, 4H), 8.21 (d, J = 8.4 Hz, 2H), 8.53 (d, J = 5.9 Hz, 1H), 11.45 (s, 1H). 13 C N MR (DMSO d 6 68.6, 74.6, 84.3, 90.3, 96.0, 122.4, 122.9, 129.6, 130.0, 132.3, 135.2, 145.6, 151.9, 154.0, 154.7, 163.0, 166.7. Anal. Calcd for C 22 H 21 N 5 O 6 : C, 58.53; H, 4.69; N, 15.51. Found: C, 58.20; H, 4.68; N, 15.36. N (1 ((2 R ,4 S ,5 R ) 4 Hydroxy 5 (hydroxym ethyl)tetrahydrofuran 2 yl) 2 oxo 1,2 dihydropyrimidin 4 yl) 4 (( E ) phenyldiazenyl)benzamide (2.15): Orange microcrystals (45%), mp 349 350C, 1 H NMR (DMSO d 6 2.11 (m, 1H), 2.29

PAGE 36

36 2.37 (m, 1H), 3.57 3.68 (m, 2H), 3.89 (d, J = 3.1 Hz, 1H), 4.25 4.26 (m, 1H), 6.15 (t, J = 6.1 Hz, 1H), 7.32 7.38 (m, 1H), 7.63 (d, J = 5.1 Hz, 3H), 7.94 7.99 (m, 4H), 8.22 (d, J = 7.6 Hz, 2H), 8.43 (d, J = 7.4 Hz, 1H), 11.38 (s, 1H). 13 C NMR (DMSO d 6 69.9, 86.3, 88.0, 122.4, 122.9, 129.6, 130.0, 132.3, 151. 9, 154.0, 167.1 Anal. Calcd for C 22 H 21 N 5 O 5 : C, 60.68; H, 4.86; N, 16.08. Found: C, 60.67; H, 4.57; N, 15.52. N (1 ((2 R ,3 R ,4 S ,5 R ) 3,4 Dihydroxy 5 (hydroxymethyl)tetrahydrofuran 2 yl) 2 oxo 1,2 dihydropyrimidin 4 yl) 4 (( E ) (4 (dimethylamino)phenyl)diazenyl) benzamide (2.1 6 ): Red microcrystals (30%), mp 225 226C, 1 H NMR (DMSO d 6 3.09 (s, 6H), 3.50 3.80 (m, 2H), 3.90 4.02 (m, 3H), 5.09 (d, J = 5.5 Hz, 1H), 5.20 5.30 (m, 1H), 5.55 (d, J = 4.7 Hz, 1H), 5.82 (d, J = 2.5 Hz, 1H), 6.89 (d, J = 9.2 Hz, 2H), 7.36 (d, J = 7.4 Hz, 1H), 7.86 (d, J = 8.5 Hz, 4H), 8.19 (d, J = 8.5 Hz, 2H) 8.61 (d, J = 7.6 Hz, 1H), 11.36 (s, 1H) 13 C NMR (DMSO d 6 95.9, 112.1, 121.5, 125.8, 130.0, 132.7, 142.6, 146.4, 153.0, 153.3, 154.6, 162.1, 166.9. Anal. Calcd for C 24 H 26 N 6 O 6 2 O: C, 56.24; H, 5.51; N, 16.40. Found: C, 56.19; H, 5.65; N, 16.05. N (1 ((2 R ,4 S ,5 R ) 4 Hydroxy 5 (hydroxymethyl)tetrahydrofuran 2 yl) 2 oxo 1,2 dihydropyrimidin 4 yl) 4 (( E ) (4 (dimethylamino)phenyl)diazenyl)benzamide (2.1 7 ): Red microcrystals (35%), mp 309 310C, 1 H NMR (DMSO d 6 03 2.11 (m, 1H), 2.29 2.38 (m, 1H), 3.09 (s, 6H), 3.56 3.68 (m, 3H), 3.88 (d, J = 3.3 Hz, 1H), 4.20 4.80 (m, 2H), 6.15 (t, J = 6.2, Hz 1H), 6.86 (d, J = 9.2 Hz, 2H), 7.37 (s, 1H), 7.84 (d, J = 8.8 Hz, 4H), 8.15 (d, J = 8.5 Hz, 2H), 8.41 (d, J = 7.3 Hz, 1H) 11.33 (s, 1H). 13 C NMR (DMSO d 6

PAGE 37

37 153.0, 154.9, 167.0 Anal. Calcd for C 24 H 26 N 6 O 5 : C, 60.24; H, 5.48; N, 17.56. Found: C, 59.87; H, 5.57; N, 17.21. 2.4.3 General Procedure f or the P reparation of 2.18, 2.22 28 N (4 arylazobenzoyl) 1 H benzotriazole (1 mmol), nucleoside (1 mmol) and 0.1 eq DMAP were stirred in DMF (5 mL) at room temperature for 24 h. After addition of dichloromethane/hexanes (2 mL/10 mL) the precipitate was filtered and purified by flash column chroma tography on silica gel (CH 2 Cl 2 : MeOH, 9:1 ) to give the corresponding dye labeled nucleoside. ((2R,3S,4R,5R) 5 (6 (4 ((E) (4 (dimethylamino)phenyl)diazenyl)benzamido) 9H purin 9 yl) 3,4 dihydroxytetrahydrofuran 2 yl)methyl 4 ((E) (4 (dimethylamino) phenyl)d iazenyl)benzoate ( 2.18 ): Red microcrystals (18%), mp 236.0 238.0 C, 1 H NMR (DMSO d 6 ) : 3. 07 ( s, 6 H), 3.08 (s, 6H), 3.76 3.93 (m, 2H) 4.56 4.62 (m, 1H), 5.87 5.97 (m, 2H), 6.33 (t, J = 6.2 Hz, 1H), 6.58 (d, J = 6.6 Hz, 1H), 6.82 (t, J = 9.5 Hz, 4H), 7.47 (br s, 2H), 7.10 7.88 (m, 8H), 7.93 (d, J = 8.5 Hz, 2H), 8.14 (d, J = 8.4 Hz, 2H), 8.20 (s, 1H), 8.49 (s, 1H). 13 C NMR (DMSO d 6 ) : 61.4, 72.6, 73.4, 84.0, 85.8, 111.6, 119.4, 121.8, 122.0, 125.5, 128.1, 128.7, 130.6, 130.7, 140.0, 142.6, 142.7, 149.0, 15 2.7, 153.1, 155.6, 155.6, 156.3, 164.0, 164.5 Anal. Calcd for C 40 H 39 N 11 O 6 : C, 62.41; H, 5.11; N, 20.01. Found: C, 62.42; H, 5.18; N, 19.74. (2 R ,3 S ,4 R ,5 R ) 5 (2,4 D ioxo 3,4 dihydropyrimidin 1(2 H ) yl) 3,4 dihydroxytetrahydrofuran 2 yl 4 (( E ) (4 (dimethylamino )phenyl)diazenyl)benzoate, ( 2.2 4 ): Red microcrystals (50%), mp 242.0 244.0 C, 1 H NMR (DMSO d 6 ) : 3.09 (s, 6H), 3.69 (br s, 2H), 4.22 4.27 (m, 1H), 4.35 4.46 (m, 1H), 5.32 5.44 (m, 2H), 5.70 5.78 (m, 1H), 5.90 (d, J = 5.9 Hz, 1H), 5.96 (d, J = 6.7 Hz, 1H), 6.85 (d, J = 8.9 Hz, 2H), 7.83 8.00 (m, 5H), 8.12 8.20 (m, 2H), 11.43 (s, 1H). 13 C NMR (DMSO d 6 ) : 39.9, 61.08,

PAGE 38

38 72.0, 73.8, 82.8, 87.3, 102.4, 111.6, 121.9, 125.4, 129.5, 130.8, 140.5, 142.7, 50.9, 153.1, 155.4, 163.0, 164.7. Anal. Calcd for C 24 H 25 N 5 O 7 : C, 58.18; H, 5.09; N, 14.13. Found: C, 58.02; H, 5.15; N, 13.68. (2 R ,3 S ,4 R ,5 R ) 5 (2,4 D ioxo 3,4 dihydropyrimidin 1(2 H ) yl) 3,4 dihydroxy tetrahydrofuran 2 yl 4 (( E ) phenyldiazenyl)benzoate (2 .2 2 ): Red microcrystals (52%), mp 236 238 C, 1 H NMR (DMSO d 6 ) : 3.60 3.74 (m, 2H), 4.24 4.29 (m, 1H), 4.36 4.48 (m, 1H), 5.34 5.45 (m, 2H), 5.70 5.80 (m, 1H), 5.92 (d, J = 6.2 Hz, 1H), 5.97 (d, J = 6.9 Hz, 1H), 7.61 7.68 (m, 3H), 7.92 8.06 (m, 5H), 8.17 8.29 (m, 2H), 11.41 (s, 1H). 13 C NMR (DMSO d 6 ) : 61.1, 72.0, 74.0, 82.7, 87.3, 102.4, 122.7, 122.8, 129.0, 129.7, 130.9, 132.4, 140.5, 150.6, 150.9, 151.9, 154. 6, 163.0, 164.5. Anal. Calcd for C 22 H 20 N 4 O 7 : C, 58.41; H, 4.46; N, 12.38. Found: C, 58.02; H,4.41; N, 12.11. (2 R ,3 S ,5 R ) 5 (2,4 D ioxo 3,4 dihydropyrimidin 1(2 H ) yl) 3 hydroxytetrahydro furan 2 yl 4 (( E ) (4 (dimethylamino)phenyl)diazenyl)benzoate (2 .2 5 ): Re d microcrystals (31%), mp 206 207 C, 1 H NMR (DMSO d 6 ) : 2.24 (m, 2H), 3.10 (s, 6H), 4.08 (d, J = 3.6 Hz, 1H), 4.45 (m, 3H), 5.56 (m, 2H), 6.20 (t, J = 6.3 Hz, 1H), 6.86 (m, 2H), 7.68 (m, 1H), 7.86 (m, 4H), 8.11 (m, 2H), 11.37 (s, 1H). 13 C NMR (DMSO d 6 ) : 39.9, 70.0, 83.6, 84.2, 101.9, 111.5, 121.8, 125.3, 1 29.2, 130.4, 140.5, 142.6, 150.3, 153.0, 155.3, 162.9, 165.1. Anal. Calcd for C 24 H 25 N 5 O 6 2 O: C, 57.94; H, 5.47; N, 14.08. Found: C, 57.92; H, 5.17; N, 13.72. (2 R ,3 S ,5 R ) 5 (2,4 D ioxo 3,4 dihydropyrimidin 1(2 H ) yl) 3 hydroxytetrahydro furan 2 yl 4 (( E ) (4 ( dimethylamino)phenyl)diazenyl)benzoate (2 .2 3 ): Orange microcrystals (45%), mp 210 211 C, 1 H NMR (DMSO d 6 ) : 2.22 2.51 (m, 2H), 4.09 4.10 (m, 1H), 4.40 455 (m, 2H), 5.53 5.60 (m, 2H), 6.21 (t, J = 6.0 Hz, 1H), 7.63 7.70

PAGE 39

39 (m, 3H), 7.95 8.18 (m, 3H), 8.19 (d, J = 8.1 Hz, 2H), 11.37 (br s, 1H). 13 C NMR (DMSO d 6 ) : 64.8, 70.1, 83.7, 84.4, 102.0, 1228.8, 122.9, 129.6, 130.7, 131.3, 132.4, 140.7, 150.4, 151.9, 154.6, 136.1, 165.0. TOF MS m/z [M + H] + calcd for C 22 H 20 N 4 O 6 : 437.1456; found: 437.1478. ((2 R ,3 S ,5 R ) 3 H ydroxy 5 (5 methyl 2,4 dioxo 3,4 dihydropyrimidin 1(2 H ) yl)tetrahydrofuran 2 yl)methyl 4 (( E ) (4 (dimethylamino)phenyl)diazenyl)benzoate (2 .2 7 ): Red microcrystal (50%), mp 230 232 C, 1 H NMR (DMSO d 6 ) : 1.63 (s, 3H), 2.12 2.34 (m, 2H), 3. 09 ( s 6H), 4. 03 4.12 (m, 1H), 4.44 (dd, J = 12.0, 5.2 Hz, 2H), 4.58 (dd, J = 12.2, 4.0 Hz, 1H), 5.51 (d, J = 4.4 Hz, 1H), 6.22 (t, J = 7.0 Hz, 1H), 6.85 (d, J = 9.2 Hz, 2H), 7.43 (s, 1H), 7.85 (t, J = 8.5 Hz, 4H), 8.11 (d, J = 8.5 Hz, 2H), 11.45 (s, 1H). 13 C NMR (DMSO d 6 ) : 12.0, 39.8, 64.6, 70.3, 83.6, 83.9, 109.8, 111.6, 121.9, 125.4, 129.3, 130.5, 135.8, 142.7, 150.4, 153.1, 155.4, 163.6, 165.2. Anal. Calcd for C 25 H 27 N 5 O 6 : C, 60.84; H, 5.51; N, 14.19. Found: C, 60.62; H, 5.20; N, 13.87. ((2 R ,3 S ,5 R ) 3 Hydroxy 5 (5 methyl 2,4 dioxo 3,4 dihydropyrimidin 1(2 H ) yl)tetrahydrofuran 2 yl)methyl 4 (( E ) phenyldiazenyl)benzoate (2 .2 6 ): Red microcrystals (54%), mp 229 230 C, 1 H NMR (DMSO d 6 ) : 1.64 (s, 3H), 2.13 2.34 (m, 2H), 4.02 4.12 (m, 1H), 3.39 4.51 (m, 2H), 4.60 (dd, J = 11.8 3.6 Hz, 1H), 5.52 (d, J = 4.3 Hz, 1H), 6.22 (t, J = 6.7 Hz, 1H), 7.44 (s, 1H), 7.59 7.68 (m, 3H), 7.90 8.00 (m, 3H), 8.01 (d, J = 8.4Hz, 1H), 8.20 (d, J = 8.4 Hz, 2H), 11.35 (s, 1H). 13 C NMR (DMSO d 6 ) : 12.0, 64.8, 70.2, 83.6, 83.9, 109.8, 122.8, 122.9 129.7, 130.7, 131.4, 132.4, 135.9, 150.4, 151.9, 154.6, 163.7, 165.0. Anal. Calcd for C 23 H 22 N 4 O 6 : C, 61.33; H, 4.92; N, 12.44. Found: C, 60.97; H, 4.95; N, 12.38.

PAGE 40

40 (2 R ,3 S ,5 R ) 5 (5 Methyl 2,4 dioxo 3,4 dihydropyrimidin 1(2 H ) yl) 2 ((4 (( E ) phenyldiazenyl)b enzoyloxy)methyl)tetrahydrofuran 3 yl 4 (( E ) phenyldiazenyl) benzoate (2 .28 ): Red microcrystals (37%), mp 233 234 C, 1 H NMR (DMSO d 6 ) : 1.67 (s, 3H), 2.55 2.76 (m, 2H), 4.54 4.78 (m, 3H), 5.68 5.76 (m, 1H), 6.36 (t, J = 6.6 Hz, 1H), 7.54 7.68 (m, 7H), 7.89 8.04 (m, 8H), 8.22 (t, J = 8.1 Hz, 4H), 11.41 (s, 1H). 13 C NMR (DMSO d 6 ) : 12.0, 35.9, 64.7, 75.1, 80.8, 84.3, 110.0, 122.7, 122.8 122.9, 129.6, 130.7, 130.9, 131.2, 131.2, 132.4, 135.9, 150.4, 151.9, 154.6, 154.6, 163.6, 164.7, 164.9. Anal. Calcd for C 36 H 30 N 6 O 7 : C, 65.65; H, 4.59; N, 12.76. Found: C, 65.60; H, 4.58; N, 13.26. 2.4.4 General Procedu re for the P reparation of 2.31 34 Equimolar quantities of N (4 arylazobenzoyl) 1 H benzotriazole (1 mmol) and the appropriate threoninol (1 mmol) were stirred in DMF (5 mL) at room temperature for 24 h. After addition of dichloromethane/hexanes (2 mL/10 mL) the precipitate was filtered and purified by flash column chromatography on silica gel (CH 2 Cl 2 : MeOH, 9:1 ) to give the corresponding dye labeled treoninol conjugates N ((2 S ,3 S ) 1,3 Dihydroxybutan 2 yl) 4 (( E ) phenyldiazenyl)benzamide ( 2.3 1 ): Pink microcrystals (60%), mp 125 126 C, 1 H N MR (CDCl 3 proton signal of exchangeable hydrogen atom is not visible ) : 1.30 (d, J = 6.3 Hz, 3H), 2. 70 2.76 (m, 1H), 3.96 4.04 (m, 3 H), 4.05 4.16 (m, 1H), 4.30 4.40 (m, 1H), 7.00 (d, J = 8.4 Hz, 1H), 7.50 7.59 (m, 3H), 7.92 8.00 (m, 6 H). 13 C NMR (CDCl 3 ) : 20.8, 54.9, 65.4, 69.3, 123.0, 123.1, 128.1, 129.2, 131.6, 169.9. An al. Calcd for C 17 H 19 N 3 O 3 : C, 65.16; H, 6.11; N, 13.41. Found: C, 65.40; H, 6.28; N, 13.20. N ((2S,3S) 1,3 Dihydroxybutan 2 yl) 2 (4 (( E ) (4 (dimethylamino)phenyl) diazenyl)phenyl)acetamide ( 2.3 2 ) : Orange microcrystals (89%), mp 224 226 C, 1 H

PAGE 41

41 NMR (DMSO d 6 proton signals of exchangeable hydrogen atoms are not visable) : 1.07 (d, J = 5.4 Hz, 3Hz), 3.06 (s 6H), 3.50 3.3.62 (m, 2H), 3.88 4.02 ( m 2H), 4.67 4.68 (m, 2H), 6.83 (d, J = 8.7 Hz, 2H), 7.79 7.87 (m, 5H), 8.01 (d, J = 8.1Hz, 2H). 13 C NMR (DMSO d 6 ) : 20.3, 39.9, 56.9, 60.5, 65.0, 111.6, 121.5, 125.2, 128.6, 135. 1, 142.7, 152.9, 154.0, 166.1. Anal. Calcd for C 19 H 24 N 4 O 3 : C, 64.03; H, 6.79; N, 15.72. Found: C, 64.38; H, 7.08; N, 15.68. N ((2 R ,3 R ) 1,3 Dihydroxybutan 2 yl) 4 (( E ) phenyldiazenyl)benzamide ( 2.3 3 ): Pink microcrystals (55%), mp 125 126 C, 1 H NMR (CDCl 3 ) : 1.30 (d, J = 6.3 Hz, 3H), 1.68 (s, 1H), 2. 58 2.74 ( m, 2H) 4.09 4.11 (m, 1H), 4.33 4.35 (m, 1H), 7.04 (d, J = 8.0 Hz, 1H), 7.52 7.54 (m, 3H), 7.97 (s, 6 H). 13 C NMR (CDCl 3 ) : 20.8, 54.9, 65.4, 69.3, 123.0, 123.1, 128.1, 129.2, 131.6, 169.9. Anal. Calcd f or C 17 H 19 N 3 O 3 : C, 65.16; H, 6.11; N, 13.41. Found: C, 65.37; H, 6.24; N, 13.28. N ((2 R ,3 R ) 1,3 Dihydroxybutan 2 yl) 4 (( E ) (4 (dimethylamino)phenyl) diazenyl) benzamide (2 .34 ): Red microcrystals (65%), mp 224 225 C, 1 H NMR (DMSO d 6 ) : 1. 0 8 (d, J = 6.3 Hz, 3H), 3.07 (s, 6H), 3.43 3.63 (m, 2H), 3.88 4.02 ( m 2H), 4.64 4.72 ( m 2H), 6.85 (d, J = 9.1 Hz, 2H), 7.79 7.85 (m, 5H), 8.02 (d, J = 8.5 Hz, 2H). 13 C NMR (DMSO d 6 ) : 20.2, 39.8, 56.8, 60.4, 64.9, 111.6, 121.5, 125.1, 128.5, 135.1, 142.6, 152.8, 153.9, 1 66.0. Anal. Calcd for C 19 H 24 N 4 O 3 : C, 64.03; H, 6.79; N, 15.72. Found: C, 63.73; H, 7.11; N, 15.45.

PAGE 42

42 CHAPTER 3 SYNTHES I S OF AMINO ACID DERI VATIVES OF QUINOLONE ANTIBIOTICS 1 3.1 Literature Overview Quinolones have been at the center of scientific and clinic al interest since they include a family of synthetic broad spectrum antibacterial drugs [ 03JAC1 ] The first generation of the quinolone antibiotics beg an with the introduction of nalidixic acid ( 3.1 ) in 1962 for treatment of uri nary tract infections in hum ans [92P57 ] Quinolones and fluoroquinolones are chemotherapeutic bactericidal drugs which eradicat e bacteria by interfering with DNA replication. Quinolones inhibit the bacterial DNA gyrase or the topoisomerase II enzyme, thereby inhibiting DNA replicati on and transcription. [98BBA29, 03JAC1109] Recent evidence has shown eukaryotic topoisomerase II to be a target for a variety of quinolone based drugs. Thus far, most of the compounds that show high activity against the eukaryotic type II enzyme contain ar omatic substituents at their C 7 positions.[ 92JBC13150 ] Quinolones enter cells easily via porins and therefore are often used to treat intracellular pathogens such as Legionella pneumophila and Mycoplasma pneumoniae For many Gram negative bacteria, DNA g yrase is the target, whereas topoisomerase IV is the target for many Gram positive bacteria. [02CMI214] First generation agents, Nalidixic acid ( 3. 1 ) oxonolic acid ( 3.2 ), cinoxacin ( 3. 3 ), and flumequine ( 3. 4 ) are used to treat gram negative bacteria (e.g urinary tract infections and psoriasis) by dermal delivery. [96P30, 85DECR331, 77JAC411, 84AAC633, 76AAC20] (Figure 3 1) 1 Reproduced with permission from Organic and Biomolecular Chemistry 2009 7 2359 Copyright 2009 The Royal Society of Chemistry

PAGE 43

43 Q uinolone antibiotics in their acid form are practically insoluble in water and also show low solubility in lipids. Due to their poor solubility, a prolonged, high dose treatment is necessary often causing gastrointestinal disturbances. Masking the carboxyl ic group potentially reduces the ulcerogenicity and affects plasma protein binding. [96P51] Figure 3 1 Selected first generation quinolone antibiotics Prodrugs formed from quinolone acids and amino acid esters are more li pophilic than the parent drugs [92P57] have healing effects on gastrointestinal lesions plus the dietary value of the amino acid. [96P30] The release of the active drug occurs in a two step process, firstly hydrolysis of the ester followed by cleavage of t he amino acid to make the quinolone acid available. [96P30] They also show enhanced in vivo antibacterial properties [ 89EU304087 85 JP 56053679 87KFZ692] with pronounced therapeutic effects against Pseudomonas aeruginosa, [ 85HU36483 85 H U36842 ] Escherichia coli, [03BMCL1635] Staphylococcus aureus [03BMCL1635] and Salmonella typhi .[87KFZ692] I n addition to other wide ranging biological activity such as anti allergic [ 85FR2564832 ] antihypert ensive, [ 85FR2564832 ] bronchodilating, [ 85FR2564832 ] properties; they bind bovine serum albumin [96P30]. Literature preparations of quinolone amino acid conjugates include the use of ethyl chloroformate, [96P30, 85FR2564832 85JP56053679 85HU36483, 85HU36842 ] a cid

PAGE 44

44 chlorides [92P57] and mixed anhydrides.(Figure 3 2) [87KFZ6 92] Utilizing amino acid esters as coupling reagents, these methods provide quinolone amino acid ester conjugates (yields 50 95%) in reaction times of 5 24h. However, coupling with free amino acids gave the target compounds in lower yields (20 50%) [ 85JP56 053679 ] Figure 3 2 Literature preparation of quinolone amino acid ester conjugates N Acylbenzotriazoles [05 S 1656] are efficient coupling reagents for N [07S3676], C [06JOC9861], and O acylation [06ST60]. When amino ac ids are used as N nucleophiles protection of the side chain (except for lysine and arginine) and the use of ester s are not required. [04S2645] N (Aminoacyl)benzotriazoles prepared from N protected amino acids have been successfully utilized for synthesis of di and tripeptides. [07JOC5794, 07BMCL6000, 08JOC5442]

PAGE 45

45 3.2 Results and Discussion The aim of this project was to synthesize amino acid conjugates of quinolones ( 3.1 4 ) by coupling the free amino acids ( 9 23 ) with the benzotriazol ides of nalidixic acid ( 3.5 ) oxolinic acid ( 3.6 ) cinoxacin ( 3. 7 ), and flumequine ( 3.8 ). 3.2.1 Preparation of the Benzotriazole Activated Quinolone Antibiotics Nalidixic acid ( 3.1 ), oxolinic acid ( 3.2 ), cinoxacin ( 3.3 ), and flumequine ( 3.4 ) were converted to their correspondin g benzotriazol ides using standard methodology. [07BMCL6000] 16b Compounds 3.5 8 were obtained in 75 90% yields (Scheme 3 1, Table 3 1) Scheme 3 1 Preparation of benzotriazole activated q uinolone antibiotics Table 3 1 P reparation of a cid b enzotriazolides ( 3.5 8 ) Entry Reactant Product Yield (%) Mp ( C) 1 Nalidixic acid ( 3.1 ) 3.5 90 169 171 2 Oxolinic acid ( 3.2 ) 3.6 75 229 232 3 Cinoxacin ( 3.3 ) 3.7 8 0 221 223 4 Flumequine ( 3.4 ) 3.8 81 218 219

PAGE 46

46 3.2.2 Preparation of Na lidixic Amino Acid Conjugates Previously nalidixic amino acid conjugates were prepared in three steps by the activ e ester method [ 85 FR 2564832 85 HU 36483 ] or in two steps by an acid chloride method [ 85 JP 56053679 ]. The coupling of 3.5 with free amino acids ( 3.9 15 ) in aqueous MeCN in the presence of Et 3 N in 3h resulted in the formation of nalidixic amino acid conjugates ( 3.16 22 ) in 54 88 % overall yields (Scheme 3 2 and Table 3 2). Scheme 3 2 Preparation of nalidixic acid amino acid conjugates 3.16 22 Table 3 2. Preparation of nalidixic a mino a cid c onjugates 3.16 22 Entry H 2 N AA OH Product Overall yield (%) Mp ( C) Lit. overall yield (%) 1 Gly ( 3.9 ) 3.16 75 259 260 54 2 L Ala OH ( 3.10 ) 3.17 81 251 253 3 DL Ala OH ( 3.11 ) 3.18 88 252 254 50 4 L Phe OH ( 3.12 ) 3.19 86 213 215 5 L Met ( 3.13 ) 3.20 58 164 165 6 L Leu ( 3.14 ) 3.21 6 0 171 172 28 7 L Val ( 3.15 ) 3.22 54 182 185 3.2.3 Preparation of Oxolinic Amino Acid Conjugates In the literature oxolinic amino acid conju gates were prepared by coupling of ester activated oxolinic acid with amino acid esters (52 66%), followed by ester hydrolysis (66 90 %) [ 85 FR 2564832 85 HU 36483 ] or by th e reaction of oxolinic acid chloride with free amino acids (18 25%) [ 85 JP 56053679 ].

PAGE 47

47 Si milarly, the coupling of 3.6 with free amino acids ( 3.9 15, 3.23 24 ) afforded oxolinic amino acid conjugates 3.25 33 in 61 82% overall yields (Scheme 3 3 and Table 3 3). Chiral HPLC (detection at 220 nm, flow rate 1.0 mL/min, and 50%MeOH as solvent) showe d a single peak for 3.28 By contrast two peaks were observed for the corresponding racemic mixture 3.32 confirming the enantiopurity of oxolyl L Phe OH 3.28 Scheme 3 3 Preparation of oxolinic acid amino acid conjugates 3.25 33 Table 3 3. Preparation of o xolinic a mino a cid c onjugates 3.25 33 Entry H 2 N AA OH Product Overall yield (%) Mp ( C) Lit. overall yield (%) 1 Gly ( 3.9 ) 3.25 78 296 298 44 2 L Ala OH ( 3.10 ) 3.26 82 257 259 18 3 DL Ala OH ( 3.11 ) 3.27 71 257 259 25 4 L Phe OH ( 3.12 ) 3.28 72 213 215 5 L Met ( 3.13 ) 3.29 74 193 194 6 L Leu ( 3.14 ) 3.30 75 219 221 40 9 L Val ( 3.15 ) 3.31 61 225 227 11 D L Phe OH ( 3.23 ) 3.32 75 248 249 12 L Trp ( 3.24 ) 3.33 61 167 171 3.2.4 Preparation of Cinoxacin and Flumequ ine Amino Acid Conjugates In order t o show the generality of the benzotriazole methodology we coupled amino acids with two other quinolone antibiotics: cinoxacin ( 3.3 ) and flumequine ( 3.4 ). Cinoxacin amino acid conjugates 3.34 36 were obtained in 58 66% ov erall yields by

PAGE 48

48 reacting 3.7 with free amino acids ( 3.10, 3.23 24 ) in aqueous acetonitrile for 3h (Scheme 3 4 and Table 3 4). Scheme 3 4 Preparation of cinoxacin amino acid conjugates 3.34 36 Table 3 4. Preparation of c inoxacin a mino a cid c onjugates 3.34 36 Entry H 2 N AA OH Product Overall yield (%) Mp ( C) 1 L Ala OH ( 3.10 ) 3.34 66 236 238 2 D,L Phe OH ( 3.23 ) 3.35 66 266 268 3 L Trp OH ( 3.24 ) 3.36 58 179 181 Under the same reaction conditions the coupling of benzotr iazole activated flumequine 3.8 with free amino acids ( 3.12, 3.24 ) afforded flumequine amino acid conjugates 3.37 38 in 43 and 45% overall yields, respectively. (Scheme 3 5 and Table 3 5). Scheme 3 5 Preparation of flume quine amino acid conjugates 3.37 38 Table 3 5 Preparation of flumequine a mino a cid c onjugates 3.37 38 Entry H 2 N AA OH Product Overall yield (%) Mp ( C) 1 L Phe OH ( 3.12 ) 3.37 43 175 176 2 L Trp OH ( 3.24 ) 3.38 45 200 202

PAGE 49

49 3.3 Conclusion In conclusion we have developed a convenient and an efficient synthesis of nalidixic oxolinic cinoxacin and flumequine amino acid conjugates, utilizing a simple two step route involving : activation of the quinolone carboxylic acids as stable benzotriazole derivatives and coupling with free amino acids in acetonitrile/ aqueous media 3.4 Experimental Section 3 .4.1 General Methods Melting points were determined on a capillary point apparatus equipped with a digital thermometer. NMR spectra were recorded in CDCl 3 or DMSO d 6 with TMS as an internal standard for 1 H (300 MHz) or solvent as an internal standard for 13 C (75 MHz). Elemental analyses were performed on a CarloErba 1106 instrument. All reactions were performed using commercially available starting materials, solven ts, and reagents without inert gas protection 3.4.2 General Procedu re for the P reparation of 3.5 8 T hionyl chloride (4.0 mmol) was added to a solution of 1 H benzotriazole (16 mmol) in methylene chloride at 25C. After 30 min. the appropriate quinolone ca rboxylic acid 3.1 4 (3.8 mmol) was added and the stirring was continued for 2h. The precipitate was filtered off, and t he filtrate was washed with water and evaporated to give the benzotriazole activated quinolone antibiotic ( 3.5 8 ). 3 (1 H Benzo[ d ][1,2,3]t riazole 1 carbonyl) 1 ethyl 7 methyl 1,8 naphthyridin 4(1 H ) one ( 3.5 ): Yellow solid ( 90 %) mp 169 171 C, 1 H NMR (300 MHz, CDCl 3 ) : 1.54 (t, J = 7.2 Hz, 3H), 2.70 (s, 3H), 4.54 (q, J = 7.1 Hz, 2H), 7.28 (d, J = 8.1 Hz, 1H), 7.50

PAGE 50

50 (t, J = 8.1 Hz, 1H), 7.66 (t, J = 7.4 Hz, 1H), 8.11 (d, J = 8.2 Hz, 1H), 8.32 (d, J = 8.2 Hz, 1H), 8.50 (s, 1H), 8.62 (d, J = 8.0 Hz, 1H). 13 C NMR (75 MHz, CDCl 3 ) : 15.2 25.1, 46.7, 114.4, 115.1, 120.0, 120.9, 121.3, 126.0, 130.0, 131.6, 136.8, 146.0, 147.5, 148.6, 163.1, 164.2, 174.5. Anal. Calcd for C 18 H 15 N 5 O 2 1/2 H 2 O : C, 63.15; H, 4.71; N, 20.46, Found : C, 62.78; H, 4.61; N, 20.06. 7 (1 H B enzo[ d ][1,2,3]t riazole 1 carbonyl) 5 ethyl [1,3]dioxolo[4,5 g ]quinolin 8(5 H ) one (3. 6 ): Yellow solid ( 75 %), mp 229 232 C, 1 H NMR (300 MHz, DMSO d 6 ) : 1.40 (t, J = 6.6 Hz, 3H) 4.39 (q, J = 6.5 Hz, 2H), 6.24 (s, 2H), 7.52 (d, J = 6.5 Hz, 2H), 7.61 (t, J = 7.6 Hz, 1H), 7 .79 (t, J = 7.8 Hz, 1H), 8.22 (t, J = 8.0 Hz, 2H), 8.67 (s, 1H). 13 C NMR (75 MHz, DMSO d 6 ) : 14.5 48.7, 97.0, 102.7, 102.8, 113.1, 113.6, 119.9, 123.3, 126.2, 130.9, 136.1, 145.4, 146.2, 146.8, 152.5, 164.9, 171.7. Anal. Calcd for C 19 H 14 N 4 O 4 1/2 H 2 O : C, 61.45; H, 4.07; N, 15.09, Found : C, 61.19; H, 3.73; N, 15.27. 3 (1 H B enzo[ d ][1,2,3]triazole 1 carbonyl) 1 ethyl [1,3]dioxolo[4,5 g]cinnolin 4(1 H ) one (3.7): White solid ( 8 0%), mp 221 223 C, 1 H NMR (300 MHz, DMSO d 6 ) : 1.42 (t, J = 7.0 Hz, 3H), 4.59 (q, J = 7 Hz, 2H), 6.33 (s, 2H), 7.48 (s, 1H), 7.69 (t, J = 7.7 Hz, 2H), 7.87 (t, J = 7.7 Hz, 1H), 8.31 (dd, J =2.5, 8.0 Hz, 2H). 13 C NMR (75 MHz, DMSO d 6 ) : 13.8, 18.0, 47.8, 52.7, 95.7, 100.8, 103.4, 123.2, 135.1, 138.1, 148.1, 154.0, 161.2, 167.7, 173.9 Ana l. Calcd for C 18 H 13 N 5 O 4 2 O: C, 58.06; H, 3.79; N, 18.81, Found : C, 58.06; H, 3.39; N, 18.71. 2 (1 H B enzo[ d ][1,2,3]triazole 1 carbonyl) 9 fluoro 5 methyl 6,7 dihydropyrido [3,2,1 ij ]quinolin 1(5 H ) one (3.8): Yellow microcrystals ( 90 %), mp 232 235 C, 1 H NMR (300 MHz, DMSO d 6 ) : 1.43 (d, J = 6.7 Hz, 3H), 2.08 2.29 (m, 2H), 3.03 3.25 (m, 2H), 4.73 (bs, 1H), 7.58 7.68 (m, 2H), 7.69 7.89 (m, 2H), 8.20 8.34 (m, 2H), 8.77 8.88 (m,

PAGE 51

51 1H). 13 C NMR (75 MHz, DMSO d 6 ) : 19.9, 21.5, 25.3, 56.5, 108.3, 108.6, 112.6, 113.6, 119.9, 120.4, 120.7, 126.3, 129.1, 129.2, 130.5, 130.9, 131.4, 131.5, 132.5, 145.4, 147.0, 160.4, 164.6, 172.3 Anal. Calcd for C 20 H 15 FN 4 O 2 : C, 66.29; H, 4.17; N, 15.46, Found: C, 66.19; H, 4.18; N, 15.14. 3.4.3 General P rocedure for N alidixi c A mino A cid C onjugates (3.16 22) A mixture of 3 (1 H Benzo[ d ][1,2,3]triazole 1 carbonyl) 1 ethyl 7 methyl 1,8 naphthyridin 4(1 H ) one (0.3 mmol), amino acid (0.3 mmol) and triethylamine (0.6 mmol) in acetonitrile water mixture (2.1 mL + 0.9 mL) was stirred at roo m temperature for 3h The acetonitrile was removed under vacuum and the residue was acidified with concentrated HCl. The precipitate was filtered washed with cold water dried under reduced pressure and recrystallized from ethanol to g ive the correspondin g amino acid conjugates ( 3.16 22 ). 2 (1 Ethyl 7 methyl 4 oxo 1,4 dihydro 1,8 naphthyridine 3 carboxamido) acetic acid (3.16): white solid (40%), mp. 256 260C. 1 H NMR (300 MHz, DMSO d 6 ) : 1.38 (t, J = 6.9 Hz, 3H), 2.66 (s, 3H), 4.08 (d, J = 5.4 Hz, 2H), 4.5 5 4.62 (m, 2 H), 7.48 (d, J = 8.1 Hz, 1H), 8.55 (d, J = 8.1 Hz, 1H), 8.97 (s, 1H), 10.07 (s, 1H). 13 C NMR (75 MHz, DMSO d 6 ) : 15.0, 24.9, 40.9, 46.0, 111.7, 119.6, 121.5, 135.9, 148.0 148.1, 163.2, 163. 9 171.3 17 5.7 Anal. Calcd for C 14 H 15 N 3 O 4 : C, 58.13; H, 5.23; N, 14.53, Found : C, 58.44; H, 5.18; N, 14.33. ( S ) 2 (1 E thyl 7 methyl 4 oxo 1,4 dihydro 1,8 naphthyridine 3 carboxamido) propanoic acid (3.17): White microcrystals (90%), m p. 251 253C. 1 H NMR (300 MHz, DMSO d 6 ) : 1.35 1.41 (m, 6H), 2.66 (s, 3H), 4.46 4.58 (m, 3H), 7.48 (d, J = 8.2 Hz, 1H), 8.54 (d, J = 8.1 Hz, 1H), 8.94 (s, 1H), 10.21 (d, J = 7.1 Hz, 1H) 13 C NMR (75 MHz, DMSO d 6 ) : 15.2, 18.4, 25.0, 46.2, 47.7, 111.7, 119.8, 121.7, 136.1, 148.2, 148.3,

PAGE 52

52 163. 5 174.2, 176.0 Anal. Calcd for C 15 H 17 N 3 O 4 2 O: C, 56.07; H, 5.96; N, 13.08, Found : C, 56.40; H, 5.99; N, 13.05. 2 (1 E thyl 7 methyl 4 oxo 1,4 dihydro 1,8 naphthyridine 3 carboxamido )propanoic acid (3.18): White microcrystals (96%), mp. 252 254C. 1 H NMR ( 300 MHz, DMSO d 6 ) : 1.35 1.41 (m, 6H), 2.66 (s, 3H), 4.46 4.56 (m, 3H), 7.48 (d, J = 8.1 Hz, 1H), 8.54 (d, J = 8.1 Hz, 1H), 8.94 (s, 1H), 10.21 (d, J = 7.1 Hz, 1H) 13 C NMR (75 MHz, DMSO d 6 ) : 15.1, 18.3, 25.0, 46.2, 47.7, 111.7, 119.8, 121.7, 136.1, 148 .2, 148.3, 163.5, 174.2, 176.0 Anal. Calcd for C 15 H 17 N 3 O 4 : C, 59.40; H, 5.65; N, 13.85, Found : C, 59.64; H, 5.63; N, 13.66. ( R ) 2 (1 E thyl 7 methyl 4 oxo 1,4 dihydro 1,8 naphthyridine 3 carboxamido) 3 phenylpropanoic acid (3.19): White microcrystals (55%) mp. 213 215C. 1 H NMR (300 MHz, DMSO d 6 ) : 1.36 (t, J = 7.0 Hz, 3H) 2.63 (s, 3H), 3.06 (dd, J = 13.5 & 7.5 Hz, 1H), 3.20 (dd, J = 13.8 & 5.1 Hz, 1H), 4.52 (q, J = 7.0 Hz, 2H), 4.80 (q, J = 7.2 Hz, 1H), 7.18 7.30 (m, 5H), 7.42 (d, J = 8.1 Hz, 1H), 8.50 (d, J = 8.3 Hz, 1H), 8.93 (s, 1H), 10.19 (d J = 7.4 Hz, 1H). 13 C NMR (75 MHz, DMSO d 6 ) : 15.0 24.9, 37.3, 46.0, 53.3, 11.5, 119.6, 121.4, 126.6, 128.3, 129.2, 135.9, 137.0, 148.1, 163.1, 163.5, 172.7, 175.7. Anal. Calcd for C 21 H 21 N 3 O 4 : C, 66.48; H, 5.58; N, 11.07, Found : C, 66.21; H, 5.77; N, 11 .17. ( R ) 2 (1 Ethyl 7 methyl 4 oxo 1,4 dihydro 1,8 naphthyridine 3 carboxamido) 4 methylsulfanylbutanoic acid ( 3.20 ) : White microcrystals (64%), mp. 164 165C. 1 H NMR (300 MHz, DMSO d 6 ) : 1.33 (t, J = 6.9 Hz, 3H), 1.91 2.15 (m, 6H), 2.51 (m, 1H), 2.60 (s 3H), 4.49 (q, J = 6.9 Hz, 2H), 4.59 4.66 (m, 1H), 7.39 (d, J = 8.1 Hz 1H), 8.45 (d, J = 8.1 Hz 1H), 8.91 (s, 1H), 10.21 (d, J = 7.7 Hz, 1H). 13 C NMR (75 MHz, DMSO

PAGE 53

53 d 6 ) : 14.6, 15.0, 24.8, 29.5, 31.6, 46.0, 50.9, 111.6, 119.6, 121.4, 135.8, 148.0, 163.2 163.6, 173.1, 175.8 Anal. Calcd for C 17 H 21 N 3 O 4 S : C, 56.18; H, 5.82; N, 11.56, Found : C, 55.81; H, 5.82; N, 11.53. ( R ) 2 (1 Ethyl 7 methyl 4 oxo 1,4 dihydro 1,8 naphthyridine 3 carboxamido) 4 methylpentanoic acid (3.21): White microcrystals (67%), mp. 17 1 172C. 1 H NMR (300 MHz, DMSO d 6 ) : 0.9 0 0.94 (m, 6H), 1.37 (t, J = 6.6 Hz, 3H), 1.65 1.67 (m, 3H), 2.64 (s, 3H), 4. 53 455 (m, 3H), 7.44 (d, J = 8.2 Hz, 1H), 8.50 (d, J = 8.1 Hz, 1H), 8.96 (s, 1H), 10.16 (d, J = 8.0 Hz, 1H). 13 C NMR (75 MHz, DMSO d 6 ) : 15.0, 21.6, 22.8, 24.6, 24.8, 40.3 46.0, 50.2, 111.6, 119.6, 121.4, 135.8, 148.0, 163.2, 163.5, 173.9, 175.9. Anal. Calcd for C 18 H 23 N 3 O 4 : C, 62.59; H, 6.71; N, 12.17, Found : C, 62.33; H, 6.73; N, 12.29. ( R ) 2 (1 Ethyl 7 methyl 4 oxo 1,4 dihydro 1,8 naphthyridine 3 carboxamido) 3 methylbut anoic acid (3.22): White microcrystals (60%), mp. 182 185C. 1 H NMR (300 MHz, DMSO d 6 ) : 0.9 5 ( d J = 6.9 Hz, 6H), 1.39 (t, J = 7.0 Hz, 3H), 2.17 2.24 (m, 1H), 2.66 (s, 3H), 4.45 4.63 (m, 3H), 7.47 (d, J = 8.1 Hz, 1H), 8.55 (d, J = 8.1, 1H), 8.97 (s, 1H), 10.28 (d, J = 8.4 Hz, 1H) 13 C NMR (75 MHz, DMSO d 6 ) : 15.0, 17.6, 19.3, 24.9, 30.3, 46.0, 56.8, 111.7, 119.6, 121.5, 135.9, 148.0, 163.2, 163.8, 172.9, 176.0. Anal. Calcd for C 17 H 21 N 3 O 4 : C, 61.62; H, 6.39; N, 12.68, Found : C, 60.23; H, 6.46; N, 12.20. 3.4.4 General P rocedure for O xolini c A mino A cid C onjugates (3.25 33) A mixture of 7 (1 H b enzo[ d ][1,2,3]triazole 1 carbonyl) 5 ethyl [1,3]dioxolo[4,5 g ]quinolin 8(5 H ) one (0.5 mmol), amino acid (0.5 mmol) and triethylamine (1.0 mmol) in acetonitrile water mixture (3.5 mL +1.5 mL) was stirred at room temperature for 3h The acetonitrile was re moved under vacuum and the residue was acidified with concentrated

PAGE 54

54 HCl. The precipitate was filtered washed with cold water dried under reduced pressure and recrystallized from ethanol to g i ve the corresponding amino acid conjugates ( 3.25 33 ). 2 (5 Ethyl 8 oxo dihydro [1,3]dioxolo[4,5 g ]quinoline 7 carboxamido)acetic acid (3.25): White microcrystals (92%), mp. 296 298C 1 H NMR (300 MHz, DMSO d 6 ) : 1.35 (t, J = 7.0 Hz, 3H), 4.06 ( b s, 2H), 4.4 1 4.43 (m, 2H), 6.22 (s, 2H), 7.45 (s, 1H), 7.61 (s, 1H), 8.68 (s, 1H), 10.57 (d J = 4.8 Hz, 1H) 13 C NMR (75 MHz, DMSO d 6 ) : 14.6, 40.9, 48.9, 96.7, 102.6, 102.8, 110.2, 123.1, 136.1, 146.1, 14 6.3, 152.6, 1 64.6, 171.5, 174.0 Anal. Calcd for C 15 H 14 N 2 O 6 : C, 56.60 ; H, 4.43; N, 8.80, Found: C, 56.35; H, 4.41; N, 8.56. ( R ) 2 (5 Ethyl 8 oxo dihydro [1,3]dioxolo[4,5 g ]quinoline 7 carboxamido) propanoic acid (3.26): White microcrystals (96%), mp. 257 259 C 1 H NMR (300 MHz, DMSO d 6 ) : 1.32 1.41 (m, 6H), 4.13 4.52 (m, 3H), 6.23 (s, 2H), 7.47 (s, 1H), 7.60 (s, 1H), 8.69 (s, 1H), 10.48 (d, J = 7.0 Hz, 1H) 13 C NMR (75 MHz, DMSO d 6 ) : 14.6, 18.2 47.5, 48.8, 96.6, 102.5, 102.7, 110.1, 123.1, 136.0, 146.0, 146 .2, 152.5, 163.8, 174.1 An al. Calcd for C 16 H 16 N 2 O 6 : C, 57.83; H, 4.85; N, 8.43, Found: C, 58.13; H, 4.84; N, 8 .35. 2 (5 Ethyl 8 oxo dihydro [1,3]dioxolo[4,5 g ]quinoline 7 carboxamido) propanoic acid (3.27): White microcrystals (84%), mp. 257 259 C 1 H NMR (300 MHz, DMSO d 6 ) : 1. 32 1.41 (m, 6H), 4.41 4.50 (m, 3H), 6.23 (s, 2H), 7.47 (s, 1H), 7.60 (s, 1H), 8.69 (s, 1H), 10 48 (d, J = 7.2 Hz, 1H) 13 C NMR (75 MHz, DMSO d 6 ) : 14.6, 18.3, 47.5, 48.8, 96.6, 102.5, 102.7, 110.1, 123.1, 136.0, 146.0, 146.2, 152.5, 163.8, 174.0,

PAGE 55

55 174.1 A nal. Calcd for C 16 H 16 N 2 O 6 : C 57.83; H, 4.85; N, 8.43, Found: C, 57.53; H, 4.92; N, 8.46. ( R ) 2 (5 E thyl 8 oxo 5,8 dihydro [1,3]dioxolo[4,5 g]quinoline 7 carboxamido) 3 phenylpropanoic acid (3.28): White microcrystals (58%), mp. 213 215C. 1 H NMR (300 MHz, DMSO d 6 ) : 1.33 (t, J = 7.0 Hz, 3H) 3.00 3.08 (m, 1H), 3.15 3.22 (m, 1H), 4.40 (q, J = 6.0 Hz, 2H), 4.75 (q, J = 7.1 Hz, 1H), 6.23 (s, 2H), 7.19 7.30 (m, 5H), 7.46 (s, 1H), 7.60 (s, 1H), 8.67 (s, 1H), 10.49 (d, J = 7.6 Hz, 1H). 13 C NMR (75 MHz, DMSO d 6 ) : 14.6, 37.4, 48.8, 53.3, 96.6, 102.5, 102.7, 110.0, 123.0, 126.6, 128.3, 129.2, 136.0, 137.1, 146.1, 146.2, 152.5, 164.1, 172.8, 173.9. Anal. Calcd for C 22 H 20 N 2 O 6 : C, 64.70; H, 4.94; N, 6.86, Found: C, 64.34; H, 4.90; N, 6.85. ( R ) 2 (5 Ethyl 8 oxo dihydro [1,3]di oxolo[4,5 g ]quinoline 7 carboxamido) 4 methylsulfanylbutanoic acid ( 3.29 ) : White microcrystals ( 87%), mp. 193 194 C 1 H NMR (300 MHz, DMSO d 6 ) : 1.34 (t, J = 7.2 Hz, 3H), 1.93 2.13 (m, 5H), 2.50 (m, 2H), 4.43 (q, J = 7.2 Hz, 2H), 4.59 4.6 6 (m, 1H), 6.2 4 (s, 2H), 7.50 (s, 1H), 7.63 (s, 1H), 8.71 (s, 1H), 8.90 (bs, 1H), 10.53 (d, J = 7.7 Hz, 1H) 13 C NMR (75 MHz, DMSO d 6 ) : 14.6, 29.5, 31.6, 48.9 50.8, 96.7, 102.6, 102.8, 110.1, 123.1, 136.1, 146.2, 146.3, 152.6, 164.3, 173.2, 174.1 Anal. Calcd for C 18 H 20 N 2 O 6 S: C, 55.09; H, 5.14; N, 7.14, Found: C, 54.89; H, 5.06; N, 6.75. ( R ) 2 (5 Ethyl 8 oxo dihydro [1,3]dioxolo[4,5 g ]quinoline 7 carboxamido) 4 methylpentanoic acid (3.30): White microcrystals (88%), mp. 219 221C 1 H NMR (300 MHz, DMSO d 6 ) : 0.9 2 (t, J = 6.9 Hz, 6H), 1.34 (t, J = 6.9 Hz, 3H), 1.6 2 1.75 (m, 3H), 4.42 (q, J = 6.9 Hz 2H), 4.52 (q, J = 6.9 Hz, 1H), 6.23 (s, 2H), 7.47 (s, 1H), 7.61 (s, 1H), 8.70 (s, 1H), 10.46 (d, J = 7.8 Hz, 1H) 13 C NMR (75 MHz, DMSO d 6 ) : 14.6,

PAGE 56

56 21.6, 22.9, 24.6, 41.0, 48.9, 50.2, 96.6, 102.5, 102.8, 110.1, 123.1, 136.0, 146.1, 146.2, 152.6, 164.2, 174.1 Anal. Calcd for C 19 H 22 N 2 O 6 : C, 60.95; H, 5.92; N, 7.48, Found: C, 60.67; H, 5.86; N, 7.14. ( R ) 2 (5 Ethyl 8 oxo dihydro [1,3]dioxolo[4,5 g ]quinoline 7 carb oxamido) 3 methylbutanoic acid (3.31): White microcrystals (72%), mp. 225 227C 1 H NMR (300 MHz, DMSO d 6 ) : 0.95 (d, J = 6.6 Hz, 6H), 1.35 (t, J = 7.0 Hz, 3H), 2.16 2.22 (m, 1H), 4.4 0 4.4 7 (m, 3H), 6.24 (s, 2H), 7.48 (s, 1H), 7.63 (s, 1H), 8.70 (s, 1H), 10.57 (d, J = 8.5 Hz, 1H) 13 C NMR (75 MHz, DMSO d 6 ) : 14.6, 17.7, 19.4, 30.3, 48.9, 56.8, 96. 6 102.6, 10 2.7, 110.2, 123.1, 136.0, 146.1, 146.2, 152.6, 164.4, 173.0, 174.2 Anal. Calcd for C 18 H 20 N 2 O 6 H 2 O: C, 57.14; H, 5.86; N, 7.40, Found: C, 57.56; H, 5.69; N, 7.35 2 (5 Ethyl 8 oxo dihydro [1,3]dioxolo[4,5 g ]quinoline 7 carboxamido) 3 phenylpropanoic aci d ( 3.32 ) : White microcrystals (88%), mp. 248 249 C. 1 H NMR (300 MHz, DMSO d 6 ) : 1.33 (t, J = 7.0 Hz, 3H), 3.04 (dd, J = 13.5 8.0 Hz 1H), 3.18 (dd, J =13.5 8.0 Hz 1H), 4.41 (q, J = 7.0 Hz, 2H), 4.75 4.77 (m, 1H), 6.23 (s, 2H), 7.22 7.30 (m, 5H), 7.47 (s, 1H), 7.61 (s, 1H), 8.67 (s, 1H), 10.49 (d, J = 7.8 Hz, 1H). 13 C NMR (75 MHz, DM SO d 6 ) : 14.5, 37.4, 48.8, 53.3, 96.6, 102.5, 102.7, 110.0, 123.0, 126.6, 128.2, 129.2, 136.0, 137.1, 146.1, 146.2, 152.5, 164.1, 172.8, 174.0. Anal. Calcd for C 22 H 20 N 2 O 6 : C, 64.70; H, 4.94; N, 6.86, Found: C, 64.34; H, 4.90; N, 6.85. ( R ) 2 (5 Ethyl 8 oxo dihydro [1,3]dioxolo[4,5 g ]quinoline 7 carboxamido) 3 (1 H indol 3 yl)propanoic acid (3.33): White microcrystals (72%), mp. 167 171 C 1 H NMR (300 MHz, DMSO d 6 ) : 1.32 (t, J = 7.5 Hz, 3H), 3.17 3.33 (m, 2H), 4.40 (q J = 7.5 Hz, 2H), 4.79 4.83 (m, 1H), 6.23 (s, 2H), 6.92 6.97 (m, 1H), 7.02 7.07 (m, 1H), 7.18 (s, 1H), 7.31 7.34 (m, 1H), 7.46 (s, 1H), 7.54 7.61 (m, 2H ), 8.69 (s, 1H), 10.53 (d, J =

PAGE 57

57 7.5 Hz 1H), 10.91 (s, 1H) 13 C NMR (75 MHz, DMSO d 6 ) : 14.6, 27.7, 48.9, 52.7, 96.6, 102.5, 102.7 109.4, 11 0.2, 111.4, 118.4 121.0, 123.1, 123.6, 127.3, 136.0, 136.1, 146.1, 146.2, 152.5, 164.1, 173.3, 174.0 Anal. Calcd for C 24 H 21 N 3 O 6 H 2 O : C, 61.93; H, 4.55 ; N, 9.03, Found: C, 61. 71; H, 4.79; N, 9.35 3.4.5 General P rocedure for C inoxacin A mino A cid C onjugat es (3.34 36) A mixture of 3 (1 H benzo[ d ][1,2,3]triazole 1 carbonyl) 1 ethyl [1,3]dioxolo[4,5 g ]cinnolin 4(1 H ) one (0.3 mmol), amino acid (0.3 mmol) and triethylamine (0.6 mmol) in acetonitrile water mixture (2.1 mL + 0.9 mL) was stirred at room temperatur e for 3h The acetonitrile was removed under vacuum and the residue was acidified with concentrated HCl. The precipitate was filtered washed with cold water dried under reduced pressure and recrystallized from aq. ethanol to g i ve the corresponding amino acid conjugates ( 3.34 36 ). ( S ) 2 (1 E thyl 4 oxo 1,4 dihydro [1,3]dioxolo[4,5 g]cinnoline 3 carboxamido) propanoic acid (3.34): White microcrystals (82%), mp. 236 238C. 1 H NMR (300 MHz, DMSO d 6 ) : 1.38 1.43 (m, 6H), 4.4 5 4.5 0 (m, 1H), 4.5 7 4.64 (m, 2H), 6.31 (s, 2H), 7.54 (s, 1H), 7.65 (s, 1H), 10.45 (d, J = 6.9 Hz, 1H) 13 C NMR (75 MHz, DMSO d 6 ) : 15.2, 18.4, 25.0, 46.3, 47.7, 111.7, 119.8, 121.8, 136.1, 148.2, 148.3, 163.5, 174.2, 176.0. Anal. Calcd for C 15 H 17 N 3 O 7 2 O: C, 51.28; H, 4.88; N, 11.96, Found : C, 51.49; H, 4.77; N, 11.92. 2 (1 E thyl 4 oxo 1,4 dihydro [1,3]dioxolo[4,5 g]cinnoline 3 carboxamido) 3 phenylpropanoic acid (3.35): White microcrystals (82%), mp. 266 268C. 1 H NMR (300 MHz, D MSO d 6 ) : 1.39 (t, J = 7.1 Hz, 3H), 3.03 3.10 (m, 1 H), 3.20 (dd, J = 4.9 13.9 Hz, 1H), 4.58 ( q J = 7 .0 Hz, 2H), 4.7 3 4.80 (m, 1H), 6.29 (s, 2H), 7. 19 7.30 (m, 5H), 7.51 (s, 1H), 7.61 (s, 1H), 10.45 (d, J = 7.4 Hz, 1H) 13 C NMR (75 MHz, DMSO d 6 )

PAGE 58

58 : 13.7, 37.1, 52.7, 53.5, 95.7, 100.8, 103.4, 123.2, 126.6, 128.3, 129.2, 134.8, 137.0, 138.1, 148.1, 153.9, 161.4, 167.7, 172.5. Anal. Calcd for C 21 H 19 N 3 O 6 : C, 61.61; H, 4.68; N, 10.26, Found : C, 61.28; H, 4.55; N, 10.21. ( S ) 2 (1 E thyl 4 oxo 1,4 dihydro [1,3]di oxolo[4,5 g]cinnoline 3 carboxamido) 3 (1H indol 3 yl)propanoic acid (3.36): White microcrystals (73%), mp. 179 181C. 1 H NMR (300 MHz, DMSO d 6 ) : 1.39 (t, J = 6.9 Hz, 3H), 3.26 (m, 2H), 4.59 (q, J = 6.9 Hz, 2H), 4.81 (q, J = 6.3 Hz, 1H), 6.30 (s, 2H), 6.94 (t J = 7.4 Hz, 1H), 7.05 (t, J = 7.6 Hz, 1H), 7.1 9 (s, 1H), 7.32 (d, J = 8.1 Hz, 1H), 7.50 ( b s, 1H), 7.54 (d, J = 8.0 Hz, 1H), 7.64 (s, 1H), 10.49 (d, J = 7.1 Hz, 1H), 10.90 (s, 1H) 13 C NMR (75 MHz, DMSO d 6 ) : 13.7, 52.7, 53.0, 95.7, 100.8, 103.4, 109.2, 111.4, 118.4, 121.0, 123.2, 123.7, 127.3, 135.0, 136.1, 138.1, 148.0, 154.0, 161.4, 167.7, 173.0. Anal. Calcd for C 23 H 22 N 4 O 7 2 O: C, 59.22; H, 4.75; N, 12.01, Found : C, 59.47; H, 4.71; N, 12.50. 3.4.6 General P rocedure for F lumequ ine A mino A cid C onjugates (3.37 38 ) A mixture of 2 (1 H b enzo[ d ][1,2,3]triazole 1 carbonyl) 9 fluoro 5 methyl 6,7 dihydro pyrido[3,2,1 ij ]quinolin 1(5 H ) one (0.3 mmol ), amino acid (0.3 mmol) and triethylamine ( 0.6 mmol) in acetonitrile water mixture (2.1 mL + 0.9 mL) was stirred at room temperature for 3h The acetonitrile was removed under vacuum and the residue was acidified with concentrated HCl. The precipitate was filtered washed with cold water dried under reduced pressure and recrystallized from ethanol to g i ve the corresponding amino acid conjugates ( 3.37 38 ) (2 R ) 2 (9 Fluoro 5 methyl 1 oxo 1,5,6,7 tetrahydropyrido[3,2,1 ij]quinoline 2 carboxamido) 3 phenylpr opanoic acid ( 3.37 ) : White microcrystals (53%), mp. 175 176C. 1 H NMR (300 MHz, DMSO d 6 ) : 1.36 (d, J = 6.6 Hz, 3H), 2.09 (bs, 2H), 3.00 3.40 (m, 4H), 4.78 4.80 (m, 2H), 7.15 7.30 (m, 5H), 7.60 (dd, J = 9.0, 3.0 Hz, 1H), 7.80

PAGE 59

59 (dd, J = 8.7, 2.7 Hz, 1H), 8.80, (s, 1H), 10.25 (d, J = 7 Hz, 1H). 13 C NMR (75 MHz, DMSO d 6 ) : 20.0, 21.5, 25.3, 37.3, 53.3, 53.4, 56.5, 108.1, 108.4, 109.8, 120.3, 120.6, 126.6, 128.3, 128.9, 129.2, 131.3, 131.4, 132.4, 137.0, 137.1, 146.3, 157.1, 160.3, 163.8, 163.9, 172.7, 174.6. Anal. Calcd for C 23 H 21 F N 2 O 4 : C, 67.64; H, 5.18; N, 6.86, Found : C, 67.38; H, 5.18; N, 6.81 (2 R ) 2 (9 Fluoro 5 methyl 1 oxo 1,5,6,7 tetrahydropyrido[3,2,1 ij]quinoline 2 carboxamido) 3 (1 H indol 3 yl)propanoic acid ( 3.38 ) : White microcrystals (56%), mp. 202 203C. 1 H NMR (300 MHz, DMSO d 6 ) : 1.40 (d, J = 6.6 Hz 3H ), 2.14 ( bs 2H), 3.00 3.50 ( m, 4H), 4.86 ( m, 2H), 6.98 (t, J = 7.2 Hz, 1H) 7.08 (t, J = 7.2 Hz, 1H ), 7.20 (s 1H ) 7.36 (d, J = 6.9 Hz, 1H ), 7.58 7.66 ( m, 2H), 7.81 7.84 ( m, 1H), 8.85 ( s, 1H), 10.39 (d, J = 7 Hz 1H ), 10.93 ( s, 1H) 13 C NMR (75 MHz, DMSO d 6 ) : 20.0, 21.5, 25.3, 27.7, 52.7, 56.5, 108.0, 108.3, 109.3, 110.0, 111.4, 118.4, 120.3, 120.6, 121.0, 123.7, 127.3, 128.8, 128.9, 131.4, 131.5, 132.4, 136.1, 146.3, 157.1, 160.3, 163.9, 173.3, 174.5, 174.6. Anal. Calcd for C 25 H 22 F N 3 O 4 2 O: C, 64.51; H, 5.20; N, 9.03, Found : C, 64.44; H, 5.13; N, 8.84.

PAGE 60

60 CHAPTER 4 SYNTHESIS OF NOVEL U NSYMMETRICAL PYRROLO [3,2 B]PYRROLE 2,5 DIONES 4.1 Literature Overview Diketopyrrolopyrroles (DPP) as synthetic pigments are of great interest i n material sciences. The basic skeletal framework of these dyes consists of two annulated five membered rings each of which contains a carbonamide moiety in the ring. [76CR625], [97IOP9] The most commonly used skeletons are the derivatives of pyrrolo[3,4 c ]pyrrole 1,4 dione ( 4. 1 ) and pyrrolo[3,2 b ]pyrrole 2,5 dione ( 4. 2 ). (Figure 4 1 ) Figure 4 1 Most commonly used DPP pigment skeletons In full shades and white reductions, these pigments afford shades in the color range fro m orange to medium and bluish reds [97IOP9] and are useful as components of inks, colorants, pigmented plastics for coatings, non impact printing material, color filters, cosmetics, polymeric ink particles, toners, fluorescent tracers, in color changing m edia, dye lasers, and electroluminescent devices. [ 07 WO2007003520A1] Favorable properties include their optical features, their stability against degradation at high temperatures, and low solubility. 4.1.1 Optical Properties The optical properties of the pyrrolo[3,2 b ]pyrrole 2,5 diones having identical substituents at N 1 and N 4 ( 4. 3 ) were determined and revealed that wavelength and 1 ) in the UV vis spectra are not significantly influenced by substitution in the phenyl g roups on the carbonamide nitrogen or by R 3 on

PAGE 61

61 the heterocyclic core (Table 4 1). In contrast, substitution at positions 3 and 6 of the heterocyclic core influences observed [00JOC729]. (Table 4 1). T able 4 1. Optical properties of the symmetrically substituted pyrrolo[3,2 b ]pyrrole 2,5 diones ( 4.3 ) [00JOC729] Entry max (nm) R 1 R 3 1 (n 2 3 1 H phenyl 246 344 2 4 methyl phenyl 267 366 3 4 tert buthyl phenyl 255 349 4 4 methoxy phenyl 244 341 5 3 triflouromethyl phenyl 243 345 6 4 methyl H 247 294 387 7 4 methyl benzyl 247 300 397 8 4 methyl dimethylamino 254 414 9 4 methyl 4 NMe 2 phenyl 272 457 10 4 methyl thiophene 261 302 536 The optical properties of the pyrrolo[3,2 b]pyrrole 2,5 diones with different subtituents at N 1 and N 4 ( 4. 4 ) were also studied by Langer et al. who found that the substituents on the nitrogen do not affect the absorption wavelength. However, a b 3 at positions 3 and 6 become more electron donating (Table 4 2). [06S2507] To summarize, the optical properties of substituted pyrrolo[3,2 b ]pyrrole 2,5 diones both with identical and d ifferent substituents at N 1 and N 4 are not significantly influenced by the nature of the substituents.

PAGE 62

62 Table 4 2. Optical properties of the a symmetrically substituted pyrrolo[3,2 b ]pyrrole 2,5 diones ( 4. 4 ) [0 6S2507 ] Entry max (nm) R 1 R 2 R 3 1 phenyl 4 OMe phenyl 4 Me phenyl 361 2 phenyl 2,4 Me 2 phenyl 4 Me phenyl 363 3 4 Me phenyl 4 OMe phenyl 4 Me phenyl 361 4 4 NO 2 phenyl 4 OMe phenyl 4 Me phenyl 357 5 phenyl 4 OMe phenyl phenyl 347 6 phenyl 4 OMe phenyl 4 OMe phenyl 383 However, the optical properties of derivatives with different substituents at position s 3 and 6 were no t yet studied because of difficulties associated with availability. It was therefore important to see if such derivatives offered impro ved optical properties, especially absorption in the near IR region. [00JOC729, 88ACIE1437] 4.1.2 Synthesis of S ymmetrical P yrrolo[3,2 b ]pyrrole 2,5 diones A convenient one pot synthesis of the pyrrolo[3,2 b ]pyrrole 2,5 diones with identical substituents a t position 1 and 4 was developed by Langer et al. starting from bis(imidoyl) chlorides ( 4. 5 ) of oxalic acid [97TL5269], [00JOC729]. This reaction proceeds by condensation of two equivalents of an ester ( 4. 6 ) with the bis(imidoyl) chloride ( 4. 5 ) to give th e open chain intermediate ( 4. 7a ), which rapidly equilibrates to the enamine tautomers ( 4. 7b, 4.7c, and 4. 7d ). The dioxopyrrolopyrrole ( 4. 3 ) is formed by a two fold cyclization of tautomer 4. 7b and is removed from the equilibrium by its low solubility. Pyrr olidinone ( 4. 8 ) was obtained as a side product by the mono cyclization of tautomer ( 4. 7d ). [00JOC729]. (Figure 4 2 )

PAGE 63

63 Figure 4 2 One pot synthesis of symmetrical pyrrolo[3,2 b [pyrrole 2,5 diones ( 4. 3 ) Bis(imidoyl) chlorides ( 4. 5 ) were prepared as shown on Figure 4 3. [03S2389, 06S2507, 08S3071] The reaction of oxalyl chloride ( 4. 9 ) with different primary amines ( 4. 10 ) gave oxalamides ( 4. 11 ) which on heating under reflux in toluene with phosphorus pentachloride gave bis(imido yl) chloride ( 4. 5 ). Figure 4 3 Preparation of bis(imidoyl)chlorides ( 4. 5 ) 4.1.3 Synthesis of Unsymmetrical Pyrrolo[3,2 b ]pyrrole 2,5 diones In a similar manner, compounds with different substituents at N 1 and N 4 were syn thesized using unsymmetrical bis(imidoyl) chloride derivatives ( 4. 12 ). [03S2389, 06S2507, 08S3071] The reaction of ethyl 2 chloro 2 oxoacetate ( 4. 13 ) with primary amines ( 4. 10 ) gave ethyl 2 oxo 2 aminoacetates ( 4. 14 ). The reaction of 4. 14 with different pr imary amines afforded the unsymmetrical oxalamides ( 4. 15 ), which were subsequently converted to the unsymmetrical bis(imidoyl) chlorides ( 4. 12 ) again by

PAGE 64

64 heating under reflux in toluene in the presence of phosphorus pentachloride. (Figure 4 4) Figure 4 4 Synthesis of pyrrolo[3,2 b ]pyrrole 2,5 diones ( 4. 4 ) with different substituents at the nitrogen atoms The method described above however, cannot be used for dioxopyrrolopyrrole derivatives with different substituents at pos itions 3 and 6. Previously, such pyrrolo[3,2 b]pyrrole 2,5 dione derivatives ( 4. 19 ) were obtained by a three step protocol starting with (N phenylacetyl) acetic acid amino ester ( 4. 16 ) [ 87 DE3525109A1], or in one step from pulvinic acid ( 4. 20 ) using harsh r eaction conditions [ 85 EP0163609A2]. (Figure 4 5 ) However, pulvinic acid derivatives are not commercially available, and their syntheses also require seven additional steps. [06EJOC1489] These methods are used to obtain unsymmetrical substitution at carbon but there are no known examples of unsymmetrically substituted derivatives on nitrogen prepared by these methods.

PAGE 65

65 Figure 4 5 Synthesis of asymmetrical pyrrolo[3,2 b ]pyrrole 2,5 diones ( 4. 19 ) 4.1.4 Synthesis of Bis(i mino ) B enzotriazole Bis(imino)benzotriazoles ( 4. 2 2 ) were shown to be a superior alternative to bis imidoylchlorides derived from oxalic acid during the synthesis of indigodianiles. The authors state that the use of bis imino benzotriazoles improved the yield of their target compound due to the fact that benzotriazole is a good leaving group and has lower nucleophilicity. Also, this reagent, in contrast to the bis imidoylchlorides, is crystalline and stable to hydrolysis [06JHC1569]. Bis imino benzotriazoles ( 4.22 ) have been prepared by two differing synthetic routes. The first started from oxalyl chloride ( 4.9 ) which was converted to the corresponding bis imidoyl chloride ( 4.5 ) followed by substitution of the chlorines with benzotriazole in the presence of base. [ 08S3071, 06JHC1569] Alternatively, it was prepared from thiophosgene ( 4.23 ), which upon reaction with excess benzotriazole afforded bis benzotriazoylmethanethione ( 4.24 ). [07ARKIVOC142] Bis benzotriazoylmethanethione ( 4.24 ) then reacts readily with oxalami des ( 4.11 ) in the presence of trimethylsilylchloride (TMS Cl) to give the desired bis(imino)benzotriazole ( 4.22 ). [01JOC5601] (Figure 4 6 )

PAGE 66

66 Figure 4 6 Synthesis of bis ( imi d o yl) benzotriazole ( 4.22 ) 4.2 Results and Discussio n The aim of the project was to develop an efficient method for the preparation of pyrrolo[3,2 b]pyrrole 2,5 dione derivatives possessing different substituents at position 3 and 6 of the heterocyclic core and assessment of their photophysical properties. 4.2.1 Preliminary Investigation of the Photoph y sical Properties A preliminary theoretical investigation of the photophysical properties a series of pyrrolo[3,2 b ]pyrrole 2,5 diones bearing various EWG (electron withdrawing) and EDG (electron donating) grou ps was carried out by Dr. L. K. Beagle ( Table 4 3 ) O ptimiz ations at the B3LYP/6 31G* level of theory gave HOMO LUMO and hence the max values for a series of p yrrolo[3,2 b ]pyrrole 2,5 diones (Table 4 3). The values shown in Table 4 3 indicate that symmetri cal p yrrolo[3,2 b ]pyrrole 2,5 diones (entries 1 3) are characterized by c omputed max values ranging from 291 to 381 nm, i.e. max

PAGE 67

67 Table 4 3 Computed max values for a representative series of pyrrolo[3,2 b ]pyrrole 2,5 diones Entry R 1 R 2 R 3 R 4 max (n m) 1 H H H H 291 2 phenyl phenyl H H 372 3 phenyl phenyl phenyl phenyl 381 4 4 nitrophenyl phenyl phenyl phenyl 399 5 4 nitrophenyl 4 toluelyl phenyl phenyl 405 6 4 nitrophenyl 4 dimethylaminophenyl phenyl phenyl 504 values in the UV Vis region of the electromagnetic spectrum. Unsymmetrical DDPs are characterized by increasing max values a trend confirmed for the mismatched cases (R 1 = EWG, R 2 = EDG). In particular, DPPs bearing a strong EWG at R 1 and a strong EDG at R 2 display a net bathochromic shift with max values around 500 nm, closer to the near IR area of the electromagnetic spectrum. These results encouraged the synthetic investigation. 4.2.2 Synthetic Investigations In order to introduce flexibility and the possibility of a diverse substi tution pattern, the proposed synthesis started from bis(imidoyl)benzotriazole ( 4.26 ). It was shown previously by Katritzky et al. that the benzotriazole derivative of oxalyl chloride may be reacted with different amines in a stepwise fashion to provide un symmetrical tetrasubstituted oxamides. [98S153] (Figure 4 7) Also, b is(imido yl) benzotriazoles were shown to be superior alternative of bis ( imidoyl ) chlorides during the synthesis of indigodianiles. The authors state that using bis ( imi d o yl) benzotriazoles imp roved the yield due to the fact that benzotriazole is a good leaving group and it has lower nucleophilicity [06JHC1569].

PAGE 68

68 Figure 4 7 Substitution of the benzotriazole in a stepwise fashion Thus, bis(imidoyl)benzotriazole ( 4.26 ) was prepared in good yield, using aniline as the amine coupling partner as previously reported in the literature. [ 06JHC1569 ] Further reactions of 4.26 with different nucleophiles under various conditions were carried out and the results are summariz ed in Table 4 4. Scheme 4 1 Synthesis of compound bis(imidoyl)benzotriazole 4.26 Table 4 4 Reaction condition s for benzotriazole derivative ( 4.26 ) Entry Nu (1 eq.) Base Conditions Result 1 NaOMe rt, MeOH N.R. 2 NaO Me MW, 50C, 50W, toluene N.R. 3 PhOH NaH rt, THF, o/n N.R. 4 B n NH 2 TEA rt, THF, o/n N.R. 5 ethyl 2 phenylacetate K 2 CO 3 rt, THF, o/n N.R. 6 ethyl 2 phenylacetate K 2 CO 3 reflux, THF, o/n N.R. 7 ethyl 2 phenylacetate NaH rt, THF, o/n N.R. 8 ethyl 2 ph enylacetate BuLi 78C to rt, THF, o/n N.R.

PAGE 69

69 The total lack of reactivity for compound 4.26 was investigated by means of computational chemistry. Several theoretical studies have show n that analysis of the reactivity indexes defined within conceptual DFT a t the ground state of the reagents are able to furnish information about reactivity. The global electrophilicity index ( ), a measure of the capability of a molecule to accept electrons, was computed accord ing to the procedure of Domingo [08JOC4615] [07CPL 341] [06EJOC2570] [02JPC6871] at the B3LYP/6 31G* level of theory by Dr. Jean Christophe Monbaliu Global electrophilicities were computed for compounds 4.25 27 (Figure 4 8, Scheme 4 2 ). 4.25 4.26 4.27 Figure 4 8 Computed structures for 4.25 27 The following scale of reactivity was obtained: 4.27 ( = 2.6 eV) > 4.25 ( = 2.4 eV) > 4.26 ( = 2.0 eV). Compound 4.27 showed the highest electrophilicity, wh ile compound 4.26 was found to have the lowest ( = 2.0 eV). The computational results are in good agreement with the observed lack of reactivity of compound 4.26 and the reported lack of selectivity for compound 4.25 Analysis of the optimized structures revealed the presence of hydrogen bonding like short contacts involving the imidazoyl moiety in compound 4.27 that may be responsible for an increase in electrophilicity. Stacking drastically reduced the accessibility to the electrophilic centers in co mpound 4.26 and therefore decreased the global reactivity.

PAGE 70

70 Encouraged by the fact that the global electrophilicity for the bis(imidoyl)imidazole ( 4.27 ) was the greatest, we decided to use compound 4.27 Imidazole is also a better leaving group then benzot riazole and is less sterically hindered around the reaction center (Figure 4 8). Bis(imidoyl)imidazole ( 4.27 ) was synthesized in good yield by the same method as the benzotriazole derivative. (Scheme 4 2) Scheme 4 2 Synt hesis of compound bis(imidoyl)imidazole 4.27 Compound 4.27 was reacted with ethyl 2 phenylacetate ( 4.28 ) in the presence of NaH in THF. After column chromatography the isolated product was identified by NMR, CHN and X ray analyzes as 4.29, resulting from C laisen condensation of the ester, which generated the ethox i de nucleophile Scheme 4 3 Formation of the side product 4.29 from bis(imidoyl)imidazole ( 4.27 ) T he reaction was attempted with sodium methoxide in methanol, wh ich resulted in a double substitution, due to the small size of the reagent. Reaction with sodium ethoxide gave mono substituted product 4. 29 in 3 6% yield. Then, ethyl 2 phenylacetate was used under different conditions and the results are summarized in Ta ble 4 5.

PAGE 71

71 Table 4 5 Reaction conditions for the imidazole derivative ( 4.27 ) Entry Nu (1 eq.) Base Condition Result 1 NaOMe rt, o/n, MeOH Double sub. 2 NaOEt rt, o/n, Et OH 3 6% ( 4.29 ) 3 ethyl 2 phenylacetate BuLi 78C to rt, THF, o/n N.R. 4 ethyl 2 phenylacetate DBU rt, THF, o/n N.R. 5 ethyl 2 phenylacetate DBU MW, 50C, toluene N.R. 6 ethyl 2 phenylacetate LDA 78C to rt, THF, 2d mixture 7 ethyl 2 phenylacetate LiHMDS 78C to rt, THF, 2d N.R. 8 ethyl 2 phen ylacetate NaH rt, THF, o/n ~35% The conditions in Entry 6 (Table 4 5) gave an inseparable mixture o f the starting material and the product. Further optimization of Entry 6 (Table 4 5) was carried out by changing the order of addition, which resulted in d ecomposition of the starting materials and only trace amounts of product. The conditions in Entry 8 gave a product of which structure needs further elucidation W e decided to try the qua ternization of the imidazole nitrogen in 4.27 The goal was to perform monoqua ternization of compound 4.27 in order to facilitate the sequential addition but none of the attempts were successful.

PAGE 72

72 4.3 Conclusion In summary, a considerable effort was made to synthesize the desired unsymmetrical p yrrolo[3,2 b ]pyrrole 2,5 diones Further investigation of the reactions discussed above, especially entry 6 and 8 in Table 4 5 may afford more insight into the reactivity of the bis(imidoyl)imidazole ( 4.27 ), which would allow optimization of the conditions and achieve synthesis of the t argeted compounds. 4.4 Experimental Section 4 .4.1 General Methods Melting points were determined on a capillary point apparatus equipped with a digital thermometer. NMR spectra were recorded in CDCl 3 or DMSO d 6 with TMS as an internal standard for 1 H (300 MHz) or solvent as an internal standard for 13 C (75 MHz). Elemental analyses were performed on a CarloErba 1106 instrument. All reactions were performed using commercially available starting materials, solvents, and reagents without inert gas protection 4.4.2 Preparation of (N,N'Z,N,N'Z) N,N' (1,2 bis(1H benzo[d][1,2,3]triazol 1 yl)ethane 1,2 diylidene)dianiline (4.26) Bis( imidoyl ) chloride (3.15 g, 11.37 mmol) was dissolved in dioxane, then triethylamine (5 mL, 34.11 mmol) and benzotriazole (3.4 g, 28.43 mmol) w ere added and the mixture was heated under reflux overnight. After cooling to room temperature the solvent was evaporated under reduced pressure. The residu e was recrystallized from ethanol/ dichloromethane to give (N,N'Z,N,N'Z) N,N' (1,2 bis(1H ben zo[d][1,2,3]triazol 1 yl)ethane 1,2 diylidene)dianiline (4.5 g, 10.17 mmol) in 89% yield. Mp: 155.0 156.0 C. 1 H NMR (CDCl 3 6.54 6.61 (m, 4H), 7.09 7.21 (m, 6H),

PAGE 73

73 7.54 (t, J = 6.0 Hz, 2H), 7.66 (t, J = 8.1 Hz, 2H), 8.14 (d, J = 6.6 Hz, 2H), 8.45 (d, J = 6.6 Hz, 2H) 4.4.3 Preparation of (N,N',N,N') N,N' (1,2 di(1H imidazol 1 yl)ethane 1,2 diylidene)dianiline (4.27) Imidazol e (1.0 g, 15 mmol) was dissolved in dioxane and triethylamine (2.1 mL, 15 mmol) followed by N'1,N'2 diphenyloxalimidoyl dichloride (1.4 g, 5 mmol) w ere added. The mixture was heated under reflu x overnight. The solvent was evaporated under reduced pressure and the residue was purified by column chromatography (dichloromethane methanol) to give N,N' (1,2 di(1H imidazol 1 yl)ethane 1,2 diylidene)dianiline (1.1 g, 3.25mmol) in 65% yield. Mp: 122.0 124.0 C. 1 H NMR (CDCl 3 6.48 (dd, J = 8.1, 1.8 Hz, 4H), 7.13 7.21 (m, 8H), 7.48 (t, J = 1.5 Hz, 2H), 8.11 (s, 2H) 13 C NMR (CDCl 3 116.4, 120.5, 126.8, 129.4, 132.0, 136.0, 140.3, 144.3 4.4.4 Preparation of ethyl 2 (1H imidazol 1 yl) N phenyl 2 (phenylimino) acetimidate (4.29) NaH 60% was added t o a solution of ethyl 2 phenylacetate in te t rahydrofuran and was stirred at room temperature for 5 minutes. N,N' (1,2 di(1H imidazol 1 yl)ethane 1,2 diylidene)dianiline was added and the solution was heated under reflux for 5 h The organic solvent was evaprated and the organic concentrate was sep a rated using column chromatography ethyl acetate / h eptane 1:1 to give a yellow powder (35%) Sodium ethoxide ( 0.1 g, 1.5 mmol) was dissolved in ethanol (10 mL) and N,N' (1,2 di(1H imidaz ol 1 yl)ethane 1,2 diylidene)dianiline ( 0.5 g, 1.47 mmol) was added The reaction mixture was stirred overnight at room temperature. The organic solvent was evaprated and the organic concentrate was sep a rated using column

PAGE 74

74 chromatography ethyl acetate / h ex anes 1:1 to give a yellow powder ( 0.17 g, 0.53 mmol ) in 36% yield Mp: 105.0 C. 1 H NMR (CDCl 3 1.43 ( t J= 7.2 Hz 3H) 4.42 ( q J=6.9 2H) 6.20 ( dd J= 6.9 ,1.5 Hz 2H ) 6.61 ( dd, J= 6.9 ,1.5 Hz 2H), 6.97 ( m 7H) 7.54 ( m 1H ) 8.11 ( s 1H) 13 C NMR (CDCl 3 14.2 63.5 116.5 120.5 121.0 124.6 125.8 130. 8 136.4 142.3 144.5 145.5 150.5 Anal Clacd. for C 19 H 18 N 4 O : C, 71.68; H, 5.70; N, 17.60. Found: C, 71.27; H, 5.71; N, 17.32. 4.4.5 Preparation of dimethyl N' 1 ,N' 2 diphenyloxalimidate Sodium methoxide (0.04 g, 0.74 mmol) was dissolved in methanol (10 mL) and N,N' (1,2 di(1H imidazol 1 yl)ethane 1,2 diylidene)dianiline (0.25 g, 0.7 4 mmol) was added The reaction mixture was stirred overnight at room temperature. The organic solvent was evaprated and the organic concentrate was dissolved in dichlorom ethane and extracted with 1N HCl. The organic layer was dried over anhydrous magnesium sulfate and the solvent removed under reduced pressure to give yellow oil ( 0.04 g, 0.15 mmol) in 40% yield. 1 H NMR (CDCl 3 6.48 (m, 4H), 6.98 7.06 ( m, 2H), 7.09 7.18 (m, 4H) 13 C NMR (CDCl 3

PAGE 75

75 CHAPTER 5 SYNTHESIS AND APPLIC ATIONS OF BIS(QUINOX ALINO) LIGAND 5.1 Literature Overview Bis(quinoxalino) ligands comprise two quinoxaline subunits on opposite sides of one peraza crown subunit, (Figure 5 1) and the arrangement is not known in the literature. Figure 5 1. General structure of the bis(quinoxalino) ligand 5.1.1 Quinoxaline: Application and Synthesis Quinoxaline derivativ es afford a wide range of applications. Thus, substituted quinoxalines constitute building blocks for many compounds with diverse pharmacological activity: antibacterial [07IJHC283, 99P808], antifungal [06BMC6120], anticancer [95JMC4488], antitubercular [0 3EJMC791], antileishmanial [07BMCL194], antimalarial [49JCS1260], and antidepressant [90JMC2240, 06BMCL1753] activities. Quinoxaline is a bioisostere of quinoline, naphthalene, benzothiophene, pyridine, and pyrazine [11IJPTR386] which extends their field o f application to insecticides, fungicides, and herbicides [88H2481]. Some quinoxaline derivatives are capable of complexing transition metals, which makes them suitable for DNA binding [02PIAC391]. Q uinoxaline moieties are found in natural products as part s of riboflavin (vitamin B 2 )

PAGE 76

76 ( 5.1 ) and in a large class of peptide antibiotics, such as echinomycin ( 5.2 ) levomycin, and actinomycin, all active against Gram positive bacteria They are also active against transplantable tumors [ 75JACS2497, 95 SC2319, 06 ARKIVOC16, 03CC2286 ] (Figure 5 2) Figure 5 2. Selected quinoxaline natural products Quinoxaline derivatives have found application in material science as dyes [06DP45], electroluminescent materials [05CM1860], and organi c semiconductors. [01JMC2238] They also serve as rigid subunits in macrocyclic receptors used in molecular recognition. [08CC778] Due to the significant applications in the fields of medicinal, industrial, and synthetic organic chemistry, several methods h ave been developed for the synthesis of quinoxaline derivatives. Some of these methods involve condensation of 1,2 phenylenediamines with diketones, [05CC1321] or hydroxy compounds catalyzed by transition metals, such as Mn, Pd, Ru, and Cu, [02TL3971, 07TL4665, 05OL2169] 1,4 addition of 1,2 phenylenediamines to diazenylbutenes, [06JOC5897] cyclization oxidation of phenacetyl bromides, [0 1TL8115, 03Synlett2147] and oxidative coupling of epoxides with ene 1,2 diamines. [02TL3971] (Figure 5 3)

PAGE 77

77 Figure 5 3. Selected preparations of quinoxalines 5.1.2 Application and Synthesis of Peraza Crown Macrocycles P eraz a crown macrocycles are the nitrogen analogs of the well known crown ethers and both these classes have attracted attention for their cations While crown ethers bind strongly to alkali and alkaline earth metals, the nitrogen analog s with at least three nitrogen atoms bind effectively with transition and post transition metals [86PAC1445, 89TL3983]. Derivatives with suitable ring sizes and substituents have found applications, as redox metalloenzyme mimics, hydrolytic agents for non oxidative cleavage of DNA and RNA, antibodies for cancer localization and therapy [90EP0382582], and oxidative catalysts for various organic transformations. In addition, n itrogen donor macrocycles have been shown to perform effec tive, selective metal ion removal and separation. [89PAC1619] Certain 13 membered per aza crown structures have been investigated for use in water purification [10JACS9774]

PAGE 78

78 Complexation with metals can be improved by inserting rigid and/or voluminus structural fragments, such as ar omatic motifs, thus forcing the donor atoms into well arranged conformations. [04OBC1691] (Figure 5 4) Figure 5 4. Selected examples of peraza crown macrocycles The most usual synthe tic methods for peraza crown s involve r ing closure reactions with or without the formation of a Schiff base, [67JACS5780, 73JCSDT863, 79CL287, 87AJC1441] cyclocondensation to form C N single bond s [74JACS2268, 89JOC2990, 91JOC4904] condensation of a polyamine with acid chlorides, [89TL4125] ac tivated carboxylic acids, [76TL4339] unsaturated esters, [86CC1158] or (Figure 5 5) All these cyclization reaction s are in compete with polymerization. Figure 5 crown macrocycles

PAGE 79

79 T he per aza crown synthe tic methods fall into two categories: i) reaction in which the product formation is controlled by the presence of a template metal ion which interacts with heteroatoms, or ii) reactions carried out in ultra dilut e conditions without a template ion. R emoval of the template metal is difficult and in some cases, impossible. [93book539] 5.2 Results and Discussion The aim of this project was to incorporate various substituted quinoxalines into tetraazamacrocyclic structures, using a metal f ree and straightforward synthetic protocol. Combining the rigidity of the quinoxaline and the binding properties of the aza crown macrocycles we hope d to obtain useful compounds with a meld of superior properties. Our future work will involve assess ment of their potential use in decontamination of metal catalyzed reactions. Synthetic approach Substituted 1,4 dihydroquinoxaline 2,3 diones ( 5.23 26 ) were synthesized according to a literature procedure [76JHC13] by reacting substituted ortho phenylenediamine s ( 5.18 21 ) with oxalic acid ( 5.22 ) in 2N hydrochloric acid. (Scheme 5 1) Scheme 5 1. Synthesis of quinoxalinones 5.23 26 The reaction mixture was heated under reflux with the duration depending on the substituents. The re actions with unsubstituted ( 5.18 ) and the 4 nitro substituted ( 5.21 )

PAGE 80

80 ortho phenylenediamine were complete in 5 15 min, but the 4,5 dimethyl ( 5.19 ) abd the 4 COOMe ( 5.20 ) substituted phenylenediamines took 3 h. (Table 5 1) Table 5 1. Synthesis of quinoxalin ones 5.23 26 Compound number R group Reaction time (min) Yield (%) 5.23 H 15 73 5.24 4,5 dimethyl 180 84 5.25 4 COOMe 180 94 5.26 4 nitro 5 98 Substituted 1,4 dihydroquinoxaline 2,3 diones ( 5.23 26 ) were converted in good yields to the corresponding 2,3 dichloroquinoxaline derivatives ( 5.27 30 ). (Scheme 5 2) Scheme 5 2. Synthesis of 2,3 dichloroquinoxalines 5.27 30 The reactions were carried out in thionyl chloride in the presence of a catalytic amount of DMF. [76JHC1 3] The substituent effect followed the same trend on the rate as shown above. (Table 5 2) Table 5 2. Synthesis of 2,3 dichloroquinoxalines 5.27 30 Compound number R group Reaction time (min) Yield (%) 5.27 H 60 96 5.28 4,5 dimethyl 180 97 5.29 4 COOMe 180 88 5.30 4 nitro 30 86 The condensations between the 2,3 dichloroquinoxaline derivatives ( 5.27 28 ) and the mono Boc protected diamines ( 5.31 33 ) were carried out under in dioxane reflux in the presence of pyridine. (Scheme 5 3)

PAGE 81

81 Scheme 5 3. Synthesis of intermediates 5.34 38 The reaction between 2,3 dichloroquinoxaline ( 5.27 ) and 5 equivalents of N boc propylenediamine ( 5.32 ) stopped after the first condensation, giving compound 5.34 The change to a higher boiling sol vent (toluene or DMF) with prolonged reaction time resulted in decomposition. The use of microwave irradiation also yielded no desired product. Thus, the synthesis of substituted tert butyl (3 ((3 chloroquinoxalin 2 yl)amino) alkyl )carbamate s ( 5.34 38 ) was achieved by condensation of the substituted 2,3 dichloroquinoxalines ( 5.27 28 ) with 3 equivalents of N boc alkylenediamines ( 5.31 33 ) in good to excellent yields (Table 5 3). Table 5 3. Yields for intermediates 5.34 38 Compound number R group n Yield (% ) 5.34 H 0 90 5.35 H 1 88 5.36 H 2 80 5.37 4,5 dimethyl 0 96 5.38 4,5 dimethyl 1 95 The second condensation step was achieved by reaction between mono Boc protected diamines ( 5.31 33 ) and 5.34 38 (Scheme 5 4) Schem e 5 4. Synthesis of intermediates 5.39 43

PAGE 82

82 Initially sodium hydride in toluene was but there was no reaction either at room temperature or under reflux. Silver nitrate was then added and the solvent changed to dioxane, but thus resulted in a complex mixture of reaction products. The use of Cs 2 CO 3 in a 10:1 dioxane:water mixture under microwave irradiation at 160C for 1 h gave modest yields. (Table 5 4) Thermal deprotection of the boc protecting group was shown to cause the moderate yields. Table 5 4. Synt hesis of intermediate s 5.39 43 Compound number R group n Yield (%) 5.39 H 0 42 5.40 H 1 52 5.41 H 2 22 5.42 4,5 dimethyl 0 5.43 4,5 dimethyl 1 21 Subsequent deprotection of the Boc group was carried out in dioxane with concentrated sulfuric acid a nd gave the sulfate salts ( 5.44 48 ) in quantitative yields (Scheme 5 5). Scheme 5 5. Boc deprotection to give sulfate salts 5.44 48 Condensation of sulfate salts ( 5.44 48 ) with the corresponding 2,3 dichloroquinoxaline der ivatives ( 5.27 30 ) was carried out using Cs 2 CO 3 under microwave irradiation for 1 h at 160 C. (Scheme 5 6) The optimized conditions for final cyclization step are shown in Table 5 5. The use of cesium carbonate under microwave irradiation gave the cesium complex of the expected macrocycle (Table 5 5 entry 1, Scheme 5 7).

PAGE 83

83 Scheme 5 6. Synthesis of macrocycles 5.49 55 Scheme 5 7. Synthesis of macrocycle Cs + complex 5.56 Since removal of the metal ion from these macrocycles can be difficult, the method needs further investigation to find a synthesis without the use of large metal cations. Thus, pyridine was used as base but the reaction mixture decomposed after only 10 min under microwave irr adiation. (Table 5 5, entry 2) The use of sodium carbonate resulted in no reaction even after prolonged reaction time. (Table 5 5, entry 3) The in situ silylation of the free amine with HMDS followed by a neat reaction with 2,3 dichloroquinoxaline gave a c omplex reaction mixture (Table 5 5, entry 4). The use of potassium carbonate in dioxane/water mixture under microwave irradiation produced the expected product. (Scheme 5 8) Scheme 5 8. Synthesis of macrocycles 5.50 51

PAGE 84

84 Tab le 5 5. Cyclization conditions for the formation of macrocycle ( 5.49 55 ) Entry Base Condition Temperature (C) Time (min) Result 1 Cs 2 CO 3 MW a 160 60 5.56 (56%) 2 Py. MW a 160 10 Decomposition 3 Na 2 CO 3 MW a 160 60 No reaction 4 Silylation of amine Conv. b 180 20 Complex mixture 5 K 2 CO 3 MW a 160 60 5.50 (46%), 5.51 (62%) a dioxane/water 1:1 b neat 5.3 Conclusion In summary, a convenient synthesis was developed to form a new class of symmetric and unsymmertric macrocycles. The intermediates were synthesized in high yields under mild reaction conditions. Cyclization conditions were developed to avoid complexation of large metal ions to the macrocycles ( 5.49 55 ). Further development of more novel substrates is required and their chelation properties will be as sessed in due course. 5.4 Experimental Section 5 .4.1 General Methods Melting points were determined on a capillary point apparatus equipped with a digital thermometer. NMR spectra were recorded in CDCl 3 or DMSO d 6 operating at 300 MHz for 1 H and 75 MHz for 13 C with TMS as an internal standard. All microwave assisted reactions were carried out with a single mode cavity Discover Microwave Synthesizer. The reaction mixtures were transferred into a 10 mL glass pressure microwave tube equipped with a magnetic st irrer bar. The tube was closed with a silicon septum and the reaction mixture was subjected to microwave irradiation (Discover mode; run time: 180 sec.; PowerMax mode).

PAGE 85

85 5.4.2 General Procedu re for C ompound s 5.34 38 Mono Boc protected diamine (4.5 mmol) wa s dissolved in dioxane (20 mL) and pyridine (4.5 mmol) plus the corresponding 2,3 dichloroquinoxaline (1.5 mmol) w ere added. The reaction mixture was heated under reflux for 5 h, solvent was ev aporated under reduced pressure and the residue dissolved in et hyl acetate and extracted with 10 w/w% aq. citric acid (4x). The organic layer was dried over anhydrous sodium sulfate and evaporated to give compound s 5.34 38 Tert butyl (2 ((3 chloroquinoxalin 2 yl)amino)ethyl)carbamate ( 5.34 ): Orange oil (90%), 1 H NMR (CDCl 3 3.48 (m, 2H), 3.50 3.68 (m, 2H), 5.44 (br s, 1H), 6.33 (br s, 1H), 7.24 (t, J = 6.9 Hz, 1H), 7.43 (t, J = 6.9 Hz, 1H), 7.55 (d, J = 8.1 Hz, 1H), 7.65 (d, J = 8.4 Hz, 1H). 13 C NMR (CDCl 3 79.7, 1 24.9, 125.8, 127.8, 128.1, 130.1, 131.2, 136.3, 141.1, 148.4, 157.2. Tert butyl (3 ((3 chloroquinoxalin 2 yl)amino)propyl)carbamate ( 5.35 ) : Orange solid (88%), mp 85 86C, 1 H NMR (CDCl 3 J = 6.3 Hz, 2H), 3.20 3.28 (m, 2H), 3.66 3.74 (m, 2H), 5.47 (br s, 1H), 6.07 (br s, 1H), 7.37 (t, J = 8.1 Hz, 1H), 7.57 (t, J = 6.9 Hz, 1H), 7.71 7.81 (m, 2H). 13 C NMR (CDCl 3 30.0, 37.5, 38.3, 79.5, 125.2, 125.9, 128.1, 128.4, 130.3, 131.4, 136.5, 141.3, 148.5, 156.7. Tert butyl ( 3 ((3 chloroquinoxalin 2 yl)amino)butyl)carbamate ( 5.36 ) : Orange oil (80%), 1 H NMR (CDCl 3 1.58 (m, 2H), 1.60 1.70 (m, 2H), 3.07 3.21 (m, 2H), 3.51 (q, J = 6.3 Hz, 2H), 4.85 (br s, 1H), 5.61 (br s, 1H), 7.24 (t, J = 8.4 Hz, 1H), 7.46 (t, J = 8.4 Hz, 1H), 7.58 7.71 (m, 2H). 13 C NMR (CDCl 3 28.5, 40.2, 41.1, 79.2, 124.9, 126.0, 127.9, 128.2, 130.1, 131.3, 136.3, 137.9, 141.4, 148.1, 156.2.

PAGE 86

86 5.4.3 General Procedure f or the P reparation of C ompound 5.39 43 Mono Boc protected diamine (4.5 mmol) was dissolved in dioxane:water 10:1 (5 mL) and cesium carbonate (4.5 mmol) plus the corresponding compound 5.34 38 (1.5 mmol) w ere added. The reaction mixture was subjected to microwave irradiation at 160C for 1h. The solvent was evapo rated under reduced pressure, and the residue dissolved in ethyl acetate and extracted with 10 w/w% aq. citric acid (4x). The organic layer was dried over anhydrous sodium sulfate and evaporated. The residue was purified by flash columnchromatography to gi ve compound s 5.39 43 Di tert butyl ((quinoxaline 2,3 diylbis(azanediyl))bis(propane 3,1 diyl))dicarbamate ( 5.40 ): Orange oil (52%), 1 H NMR (CDCl 3 J = 6.6 Hz, 4H), 1.66 (quint, J = 6.3 Hz, 4H), 3.17 (q, J = 6.3 Hz, 4H), 3.55 (t, J = 6.3 Hz, 2H), 4.99 (t, J = 6.3 Hz, 2H) 7 1 6 7.20 (m, 2H), 7.52 7.57 (m, 2H) 13 C NMR (CDCl 3 25.3, 28.6, 40.2, 41.8, 79.7, 124.1, 125.1, 136.9, 144.3, 156.9. Di tert butyl ((quinoxaline 2,3 diylbis(azanediyl))bis(butane 4,1 diyl))dicarbamate ( 5.41 ): Orange oil (22%), 1 H NMR (CDCl 3 1.85 (m, 8H), 3.21 (q, J = 5.4 Hz, 4H), 3.57 (t, J = 6.6 Hz, 4H), 5.01 (br s, 2H), 6.64 (br s, 2H), 7.18 7.26 (m, 2H), 7.52 7.62 (m, 2H). 13 C NMR (CDCl 3 41.9, 79.8, 124. 1, 125.0, 136.6, 144.3, 157.0, 175.7 Di tert butyl (((6,7 dimethylquinoxaline 2,3 diyl)bis(azanediyl))bis(propane 3,1 diyl))dicarbamate ( 5.43 ): Orange oil (21%), 1 H NMR (CDCl 3 (quint, J = 6.0 Hz, 4H), 2.33 (s, 6H), 3.18 (q, J = 6. 3 Hz, 4H), 3.63 (t, J = 6.6 Hz, 4H), 5.59 (br s, 2H), 5.94 (br s, 2H), 7.38 (s, 2H). 13 C NMR (CDCl 3 38.0, 79.6, 125.0, 133.5, 134.7, 144.1, 157.1, 171.5.

PAGE 87

87 5.4.4 General Procedu re for the P reparation of C ompound 5.44 48 The corre sponding compound 5 .39 43 (1.5 mmol) was dissolved in acetone (5 mL) and concentrated sulfuric acid (1.5 mmol) was added dropwise. The formed precipitate was filtered and washed with acetone to give compound 5.44 48 which was used without purification. 5. 4.5 General Procedu re for the Preparation of C ompound 5.49 55 The corresponding compound 5.44 48 ( 1 .5 mmol) w ere dissolved in water ( 2 mL) and potassium carbonate was added until the solution is basic (pH 12) then the corresponding 2,3 dichloroquinoxaline 5.34 38 (1.5 mmol) in 2 mL of dioxane w ere added. The reaction mixture was subjected to microwave irradiation at 160C for 1h. The solvent was evaporated under reduced pressure, and the residue dissolved in ethyl acetate and extracted with water ( 2 x). The organic layer was dried over anhydrous sodium sulfate and evaporated. The residue was purified by flash columnchromatography to give compound s 5.49 55. 6,7,8,9,10,17,18,19,20,21 Decahydro [1,4,8,11]tetraazacyclotetradecino[2,3 b:9,10 b']diquinoxaline (5.50 ) : Yellow oil ( 46 1 H NMR (CDCl 3 1.85 2.18 ( m 4H), 3.42 3.82 ( m 8 H), 5.40 ( br s 4H), 7 1 6 7.2 2 (m, 4 H), 7.5 7 7.64 (m, 4 H) 13 C NMR (CDCl 3 28.3, 38.6, 38.8, 124.9, 125.6, 137.0, 148.4 6,7,8,9,10,11,18,19,20,21,22,23 Dodecahydro [1,4,9,12]tetraaz acyclo hexadecino[2,3 b:10,11 b']diquinoxaline (5.51) : Yellow oil ( 62 %), 1 H NMR (CDCl 3 1. 7 5 2.12 (m, 8H), 3.42 3.78 ( m 8 H), 4.20 (br s, 4H), 7.18 7.26 (m, 4 H), 7.52 7.62 (m, 4 H). 13 C NMR (CDCl 3 26.5, 27.0, 41.3, 41.5, 124.8, 125.2, 136.4, 144.5

PAGE 88

88 CHAPTER 6 BENZOTRIAZOYL NITROS O DERIVATIVES 1 6.1 Background Nitroso compounds have emerged during the last decades as prominent reagents for hydroxylation and amination reactions of a wide variety of substrates, leading to useful 1,2 o xazine, nitrone and other amino hydroxylated building blocks. [94S1107] Numerous examples of nitroso Diels Alder cycloaddition (nDA), [06EJOC2031] nitroso ene [03CR4131] and nitroso aldol reactions [07BCSJ592] have been reported with recent developments be ing focused on the asymmetric development of these reactions. [98T1317, 05CC3514] The nDA is the most illustrated nitroso reaction and was incorporated as a key step in the total synthesis of a broad range of biologically active molecules. [94S1107, 98T131 7, 06EJOC2031, 05CC3514] The unique reactivity arises mainly from the highly polarized nitrogen oxygen double bond and from the equilibration between the reactive monomer and the corresponding azoxidimer. [96JOC1047, 09JOC1450] The substitution pattern on the nitroso has a profound impact on these two key features that govern chemo regio and stereoselectivies. [01JOC5192, 10JOC5478, 10JMSTheochem49] Nitroso reagents are usually classified according to their substitution as N acylnitrosodienophiles or C nitrosodienophiles. [98T1317] N acylnitrosodienophiles are usually very reactive and must be prepared in situ from the corresponding stable hydroxamic acid in the presence of their substrate. [01TL5897] In this case, dimerization is often encountered in so lution and leads to degradation. [85JCSPTI883] C 1 Reproduced with permission from RSC Advances 20 12 2 8941. Copyright 2009 The Royal Society of Chemistry

PAGE 89

89 nitrosodienophiles are usually less reactive and isolatable, the stable azoxidimer being obser ved in the solid state. Among C nitroso dienophiles, arylnitroso derivatives are the most studied, despite the emergence of other promising reagents such as vinylnitroso LGNO). LGNO dienophiles are usually unstable but offer the synthetic advantage of affording the free 1,2 oxazine upon solvolysis of the initial cycloadduct. [94Synlett1107] chloro LGNO dien ophiles and were first reported by Wichterle and by Iffland, respectively. [47CCCC292, 56CI176] (Figure 6 1) Figure 6 1. Three step process for the formation of 1,2 oxazines in nitroso hetero Diels leaving group nitroso 6.1 Chloronitroso compounds are usually prepared from the corresponding oximes [94Synl1107] or nitronates [11TL2097] and appeared as key reagents for the total synthesis of cis zeatin [71JACS3056], tropane alkaloids [84TL5091], (+) calystegine B2, [99T:A2165] ( ) physoperuvine, [98CC2251, 00JCSPTI329] (+) epibatidine [98CC2251, 00JCSPTI329] and other biologically active molecules. [63JACS64, 90TL991, 92HCA65, 92JACS5900] Recent research has been dedicated to Lewis a cid promoted DA re actions of acetoxynitroso dienophiles, whether non chiral [04OL2449, 10T2969] or derived from amino acids. [10TA1507] They are usually obtained from the

PAGE 90

90 corresponding oxime by treatment with either hypervalent iodine derivatives [10T2969] or Pb(OAc) 4 /nucleophile. [ 06JACS9687] A cetoxynitroso compounds have also been studied for their ability to release HNO in vivo [06JACS9687] Nitrogen oxides f o r m a n interesting family of compounds involved in a plethora of physical, chemical and biological phenomena, ranging from atmospheric pollution to immune response. From the various redox congeners possible, nitroxyl (HNO) and nitric oxide ( NO) have been shown to play crucial roles in cell physiology. Recent studies have clearly distinguished the biological and pharmacologic al effects of nitroxyl and nitric oxide, although their complex and interconnected chemistries h av e generated controversy over the decades. The oxidation of HNO to NO is favored under physiological conditions, while the reverse reduction is extremely unfav orable. [2002PNAS10958] Furthermore, no clear evidence for the endogenous production of nitroxyl has been reported so far. [05CBC612, 98BJ9] Nitroxyl has been demonstrated to enhance cardiac contractility, to induce vasorelaxation and to increase plasma le vels of caclitonin gene related peptide (CGRP) without having an impact on the c yclic guanosine monophosphate (cGMP) plasma levels in contrast with nitric oxide. [92BJP779, 03PNAS5537, 09AJPHC1274] Recent reports mention possible application to prevent an d treat atherosclerosis. [09AJPHC1274] Antioxidant [07FRBM482] and cyctotoxic activities have also been reported. [98ABB66] HNO is the simplest nitroso compound and displays similar reactivity, including complexation with a wide range of metals and reactio ns with various S N and P nucleophiles. [05CCR433, 05ARPT335]

PAGE 91

91 Nitroxyl has a very short half live caused by a rapid dehydrative dimerization ( k = 8 x 10 6 M 1 s 1 ) [02PNAS7340, 05CCR433]. Its potential use as chemotherapeutic agent has therefore stimul ated the development of donors able to release nitroxyl slowly, [04TL5565, 05CTMC665, 06JACS9687, 10CC3788, 10JACS16526, 11IC3262, 11JMC1059, 11ARS1637] as well as the development of selective and quantitative detection kits. [09OL2719, 10IC6955, 11JACS116 ( sodium oxyhyponitrite 6.6 b enzenesulphonydroxami c acid 6.7 ) are amongst the most commonly used HNO donors (Figure 6 2 ), and they may also release nitric oxide under specific conditions. [04 BMCL 5565, 05CTMC665, 06JACS9687, 10CC3788, 10JACS16526, 11IC32 62, 11JMC1059, 11ARS1637] Figure 6 2 Most frequently reported HNO donors. HNO/NO selectivity depends mainly on pH, concentration and medium polarity. Miranda and Keefer were the first to introduce the concept of a nitr oxyl prodrugs by considering NONOate compound 6.9 which released HNO in the presence of esterases. [10JACS16526] Thermal decomposition of anthracenyl N hydroxyurea derived acylnitroso cycloadducts in water was reported to release HNO. [04BMCL5565] Photoind ucible HNO donors were recently introduced by Nakagawa et al (compound 6.11, Figure 6 2). Seminal work by King et al has led to the development of a series of promising acetoxy nitroso compounds ( 6.12 14 Figure 6 2) which release HNO

PAGE 92

92 slowly upon hydro lysis under physiological conditions and behave as vasorelaxant. [05CTMC665, 06JACS9687 11JMC1059, 11ARS1637] (Figure 6 3) Figure 6 acetoxy nitroso compounds C nitroso compounds bearing an elect ron withdrawing (EWG) group, are known for their in vitro and in vivo NO related vasodilating activities [00PR469]. In 2009, Toone et al demonstrated that cyano nitroso compounds also behave as NO donors. [09JOC1450] By modifying the electronic and ster ic properties of EWG nitroso compounds, a high selectivity for the delivery of single redox nitrogen oxides is possible and the mechanism is well understood. Figure 6 4. cyano nitroso compound 6.19 benzotriazoyl nitroso derivatives as a new class of reagents. 6.1.1 B enzotriazoyl N itroso D erivatives The starting oximes 6.21 26 were synthesized in 67 91% yields by literature methods. Lead (IV) acetate/benzotriazole reagent was generated in situ from lead (IV) tetraacetate with 10 equivalents of 1 H benzotriazole in DCM or THF. On addition of

PAGE 93

93 6.21 26 the reaction mixture turned blue green signaling for mation of 6.27 32 (Table 6 1). [2012LKBthesis] Table 6 benzotriazoyl nitroso compounds 6.27 32 Compound R 1 R 2 Solvent Yield (%) 6.27 Cyclohexyl DCM 59 6.27 Cyclohexyl THF 85 6.28 Cyclopentyl THF 48 6.29 Cycloheptyl THF 37 6.30 Cyclooctyl THF 39 6.31 M e Me THF 76 6.32 Me Et THF 72 It should be noted that the cyclopentyl ( 6.28 ), cycloheptyl ( 6.29 ), and cyclooctyl ( 6.30 Aromatic oxime 6.33 derived from acetophenone, failed to produce nitroso compound 6.34 Figure 6 Aromatic substrate 6.33 benzotriazoyl nitroso 6.34 Aromatic nitroso 6.35 (Figure 6 5), derived from the methyl ibuprofen ketoxime, decomposed rapid ly (within minutes), and 6.36 could not be isolated. Figure 6 benzotriazoyl nitroso derived from methyl ketoxime 6.35

PAGE 94

94 Further studies were carried out using only the most stable cyclohexyl ( 6.27 ), dimethyl ( 6.31 ), an d ethyl methyl ( 6.32 ) derivatives 6.1.2 B enzotriazoyl N itroso D erivatives The behavior of nitroso compounds 6.31 32 differed from that of 6.27 Compounds 6.31 32 formed white powders, but bright blue solutions, suggesting that the azodioxy dimer is the major form in the solid state but dissociates in solution into the monomeric nitroso derivative. In contrast, compound 6.27 was isolated as a monomeric nitroso derivative. The shelf life of compound 6.27 was more than 4 months at room temper ature, in contrast to the short shelf life of its chloro and acetoxy analogs. Compound 6.27 was submitted for single crystal X ray diffraction which confirmed the monomeric nitroso structure (Figure 6 6). Figure 6 7. X ray structure of monomer 6.27 Th e benzotriazoyl moiety appeared to be exclusively bonded at the quaternary carbon via the N2 position. From the X ray data sets, a single endo conformer of compound 6.27 was detected (nitroso group in equatorial position and endo versus the benzotriazoyl s ystem). This specific conformation may result from system interactions, electrostatic repulsion between the lone pair of the nitrogen and the

PAGE 95

95 aromatic benzotriazoyl system (exo lone pair effect) [92JACS1499] or a combination of both phenomena. 6.2 Results and Discussion 6.2.1 B enzotriazoyl N itroso D erivatives A computational investigation was undertaken (by Jean Christophe Monbaliu) in order to reasonably determine the reactivity of benzotriazoyl nitroso compound 6.27 as a potential dienophiles. The global electrophilicity was obtained according to the method of Domingo. [07CPL341] [06EJOC2570] The computed global electrophilicity ( ) allowed for a classification of the selected nitroso compounds according to their global reactivity. The following electrophilicity scale was fou nd: R HNO ~ R BtNO ( =2.6 eV) < R ClNO ( =2.7 eV) < R AcONO ( =2.9 eV), classifying these compounds as moderate electrophiles within the electrophilicity scale and suggesting that the nature of the leaving group affects their global reactivity. A similar ranki ng was obtained using the 13 C NMR (125 MHz) chemical shifts of the quaternary carbons as a probe of the respective electrophilicities. Activation barriers for the cycloaddition step were calculated using 2 (2 nitrosopropan 2 yl) 2 H benzo[ d ][1,2,3]triazole ( 6.37 X=Bt), 2 chloro 2 nitrosopropane ( 6.38 X=Cl) and 2 nitrosopropan 2 yl acetate ( 6.39 X=AcO) as model dienophiles. 2 Nitrosopropane ( 6.40 X=H) was selected as the reference and it showed relative insensitivity towards the nature of the leaving gro up (Figure 6 7). The reactivity of benzotriazoyl nitroso compound 6.27 in the reaction with 2,3 dimethylbutadiene was first compared to its chloro analog ( 6.41 ). Interestingly, the reaction with 6.27 did not lead to formation of the cycloadduct, but exclu sively to

PAGE 96

96 Figure 6 8 Picture of the TSs associated with the cycloaddition of the selected nitroso compounds with butadiene. 2 ( 1 nitrocyclohexyl) 2H benzo[d][1,2,3]triazole ( 6. 42 ), but reaction with 6.41 led to the corresponding 1,2 oxazine ( 6.43 ) Die ls Alder cycloadduct in moderate yield. (Scheme 6 1) Scheme 6 1. Comparison of the reactivities of nitroso compounds In order to account for the formation of the nitro derivative (6.42) the reaction was carried out in t he absence of the diene in methanol and the same product was isolated. The possibility of NO or HNO release was then investigated by computational means (by Dr. Jean Christophe Monbaliu). Isodesmic heat ( H iso ) for radical exchange and radical stabilizatio n energies (RSE) [10PCCP9597] were computed for a variety of substituted cyclohexane s emphasizing that the Bt 2 substituent stabilizes a radical better than the phenyl group (Table 6 2).

PAGE 97

97 Table 6 2 Isodesmic reactions for radical exchange on different cyc lohexyl substrates and corresponding radical stabilization energy (RSE) R H iso (kcal .mol 1 ) RSE (kcal.mol 1 ) Me 10.8 10.8 Cl 10.2 10.2 Ph 19.3 19.3 2 Bt 30.9 30.9 Homolytic bond dissociation energies (BDE) for th e release of nitric oxide from compounds 6.19 6.27 and 6.41 revealed that the homolytic bond rupture for benzotriazoyl compound was very close to the value obtained for the reference 6.19 (Table 6 3), [09JOC1450] emphasizing its propensity to form a stable tertiary radical by release of nitric oxide. Table 6 3. Homolytic bond dissociation energies (BDE) for compounds 6.19 6.27 and 6.41 X BDE (kcal .mol 1 ) 2 Bt ( 6.27 ) 22.4 CN ( 6.19 ) 19.8 Cl ( 6.41 ) 30.6 In contras t, the heterolytic bond dissociation leading to the formation of nitroxyl was found to be extremely disfavored in the case of 6.27 compared to 6.15 [06JACS9687] the reference for HNO donors (Table 6 4). Based on these computational and experimental resul ts a rational pathway for the formation of 6.42 is via the hemolytic bond cleavage to release nitric oxide and the

PAGE 98

98 Table 6 4. Heterolytic bond dissociation energies (BDE) for compounds 6.27 6.15 and 6.41 X BDE (kcal .mo l 1 ) 2 Bt ( 6.27 ) 189.4 O ( 6.15 ) 37.1 Cl ( 6.41 ) 211.1 stabilized radical 6.43. The formation of nitro compound 6.42 from the nitroso has literature precedent and involves oxidation by molecular oxygen.[08EJOC3279] Oxidized N 2 O reacts with the stabi lized radical 6.43 to yield 6.42 The formation of NO 2 from NO is a well known process and has been investigated by the oxidation of nitroso compounds by N 2 O 4 .[08EJOC3279] (Scheme 6 2) Scheme 6 2. Release of NO and forma tion of compound 6.42 from compound 6.27 6.2.2 Kinetic and M echanistic I nvestigations The rationale for the mechanism depicted in Scheme 6 2 was built on the following observations: (i) apparent first order k obs = 3.1, 2.0, 1.8 and 1.4 x 10 5 s 1 were det ermined in methanol, acetonitrile/water, acetonitrile and dichloromethane, respectively (Figure 3); (ii) the presence of a large excess of oxygen (bubbled through the solution) did not alter the rate of disappearance, which suggest that the hemolytic bond cleavage is the rate determining step. The exclusion of oxygen results in a complex reaction mixture. Kinetic information was obtained for the release of nitric oxide

PAGE 99

99 from compound s 6.27 and 6.31 32 followed by UV spectrophotometry at 20 C The effects of different solvents were seen by following the disappearance of the nitroso signal at max = 655.7 nm and [NO]= 10 mg mL 1 The observed lack of dependency of reaction rates on solvent polarity lends it to be seen as a hemolytic cleavage mechanism for relea se of N O since the half life of 6.27 in MeOH, CH 3 CN, and CH 2 Cl 2 was 247.6, 345.6, and 495.1 min, respectively I nclusion of water in acetonitrile (7:3 acetonitrile/water mixtur e) increased the half life slightly ( t 1/2 = 385.1 min). First order rate constan ts were k obs = 3.1, 2.0, 1.8 and 1.4 x10 3 s 1 respectively in methanol, acetonitrile/water, acetonitrile and dichloromethane (Figure 6 8 ). Figure 6 9. Half life of 6.27 as measured in various solvents. A dditional experiments using different concentratio ns ( 1, 2 and 4 mg mL 1 ) of compound 6.27 in acetonitrile gave half lives of t 1/2 = 280.3, 366.2 and 493.3 min This is 6.27 as it s azodioxy dimer at higher concentration (Figure 6 9). As per Figure 6 10 steric hindrance of the backbone on carbon impact s the release of NO ( t 1/2 = 223.6 ( 6.31 ), 247.6 ( 6.32 ) and 495.1( 6.27 ) min).

PAGE 100

100 Figure 6 10 Kinetics for dissociation at various concentrations of 6.27 Figure 6 11 Comparison of the half life of 6.27 and 6.31 32 6.3 Conclusion Benzot riazoyl nitroso compounds were conveniently obtained via oxidation of the corresponding oximes in the presence of lead tetraacetate and a large excess benzotriazole. B enzotriazoyl nitroso compounds were not reactive towards dienes, in contrast to their acetoxy analogs. An unexpected oxidation not

PAGE 101

101 EWG analogs occur ed in solution leading to the exclusive benzotriazoyl nitro compounds. The mechanism probably involves a rate determining homolytic cleavage of the parent nitroso, releasing NO which is readily oxidized in solution by air followed by subsequent recombination to yield the nitro analog. 6.4 Experimental Section 6.4.1 General Methods 1 H NMR spectra were recorded at 300 MHz and 13 C NMR spectra wer e recorded at 75 MHz on Gemini or Varian spectrometers at room temperature. The chemical shifts are reported in ppm relative to TMS as internal standard ( 1 H NMR) or to solvent residual peak ( 13 C NMR). The NMR experiments at variable temperatures (35, 45, 5 5 and 65 C) were recorded on a Varian Inova NMR spectrometer operating at 500 MHz. HRMS spectra were recorded on a LC TOF (ES) apparatus. Elemental analysis was performed on a Carlo Erba 1106 instrument. Melting points were determined on a capillary point apparatus equipped with a digital thermometer and are uncorrected. Flash chromatography was performed on silica gel 60 (230 400 mesh). All commercially available substrates were used as received without further purification. All microwave assisted reactio ns were carried out with a single mode cavity Discover Microwave Synthesizer (CEM Corporation, NC). The reaction mixtures were transferred into a 10 mL glass pressure microwave tube equipped with a magnetic stirrer bar. The tube was closed with a silicon s eptum and the reaction mixture was subjected to microwave irradiation (Discover mode; run time: 60 sec.; PowerMax cooling mode). Quantum chemical calculations were done using Gaussian 03W version 6.1.

PAGE 102

102 6.4.2 Synthesis of N itroso C ompounds 6.27 32. A solutio n of lead (IV) tetraacetate ( 4.43 g, 1 0.0 mmol) and 1H benzotriazole ( 11.9 g, 10 0.0 mmol) in THF ( 1 00 mL) was stirred for 15 min at 0 C. The resulting homogeneous solution was treated dropwise with a solution of oxime 6.21 26 ( 10.0 mmol) in THF ( 25 mL) ov e r 15 min at 0C. After 2 h, solvent was removed under reduced pressure and the brown residue was washed several times with hexanes (5 x 50 mL). The combined organic fractions were evaporated under reduced pressure and the greenish oily residue was purif ied over silica gel (hexanes /ethyl acetate 10/1) to yield pure benzotriazole nitrosos 6.27 32 Slow crystallization from a hexanes /diethyl ether mixture gave 6.27 as blue crystals 2 (1 N itrosocyclohexyl) 2H benzo[d][1,2,3] triazole 6.27 Yield: 48% (1.9 5 g), blue microcrystals. m.p. 125.0 127. 0 C. 1 H NMR (300 MHz, CDCl 3 ): = 1.34 1.51 (m, 2H), 1.55 1.67 (m, 1H), 1.67 1.80 (m, 1H), 1.94 2.06 (m, 2H), 2.65 2.86 (m, 4H), 7.36 7.45 (m, 2H), 7.84 7.93 (m, 2H) ppm. 13 C NMR (75 MHz, CDCl 3 ): = 21.7, 24.6, 29 .2, 118.7, 127.0, 128.1, 144.9 ppm. Elemental analysis calcd (%) for C 12 H 14 N 4 O 1 : C, 62.59 ; H, 6.13 ; N, 24.33 ; found: C, 62.20 ; H, 5.90 ; N, 24.41 2 (1 N itrosocyclo pent yl) 2H benzo[d][1,2,3] triazole 6.28 Yield: 76% (1.95 g), blue oil 1 H NMR (300 MHz, CDCl 3 ): = 1.34 1.51 (m, 2H), 1.55 1.67 (m, 1H), 1.67 1.80 (m, 1H), 1.94 2.06 (m, 2H), 2.65 2.86 (m, 4H), 7.36 7.45 (m, 2H), 7.84 7.93 (m, 2H) ppm. 13 C NMR (75 MHz, CDCl 3 ): = 21.7, 24.6, 29.2, 118.7, 127.0, 128.1, 144.9 ppm. Elemental analysis calcd (%) for C 12 H 14 N 4 O 1 : C, 62.59 ; H, 6.13 ; N, 24.33 ; found: C, 62.20 ; H, 5.90 ; N, 24.41 2 (1 N itroso prop yl) 2H benzo[d][1,2,3] triazole 6.31 Yield: 72% (1.95 g), blue oil 1 H NMR (300 MHz, CDCl 3 ): = 1.34 1.51 (m, 2H), 1.55 1.67 (m, 1H), 1.67 1.80 (m,

PAGE 103

103 1H), 1.94 2.06 (m 2H), 2.65 2.86 (m, 4H), 7.36 7.45 (m, 2H), 7.84 7.93 (m, 2H) ppm. 13 C NMR (75 MHz, CDCl 3 ): = 21.7, 24.6, 29.2, 118.7, 127.0, 128.1, 144.9 ppm. 2 (2 nitrosobutan 2 yl) 2H benzo[d][1,2,3]triazole 6.32 Yield: 85% (1.95 g), blue oil 1 H NMR (300 MHz, CDCl 3 ): = 1.34 1.51 (m, 2H), 1.55 1.67 (m, 1H), 1.67 1.80 (m, 1H), 1.94 2.06 (m, 2H), 2.65 2.86 (m, 4H), 7.36 7.45 (m, 2H), 7.84 7.93 (m, 2H) ppm. 13 C NMR (75 MHz, CDCl 3 ): = 21.7, 24.6, 29.2, 118.7, 127.0, 128.1, 144.9 ppm. 6.4.3 X ray D ata for 6.27 and 6. 42 Crystal data for compound 6 .27: blue crystal ( plates ), dimensions 0. 4 x 0. 1 x 0. 04 mm, crystal system monoclinic, space group P2(1)/c Z = 4, a = 11.7352(5) b = 8.5659(3) c = 12.1021(4) 110.616(2) V = 1138.63(7) 3 1.349 g cm 3 T = 100( 2) 30.60 radiation Mo 0.71073 scans with CCD area detector, covering a whole sphere in reciprocal space, 14435 reflections measured, 3407 unique (R int = 0.0218 ), 2873 Lorentz and polarization effects, an empirical absorption correction was applied using SADABS22 based on the Laue symmetry of the reciprocal space m = 0.091 mm 1 Tmin = 0.6840 Tmax = 0.7461 structure solved by directmethods and refined against F2 with a Full matrix least squares algorithmusing the SHELXL 97 software package, 164 parameters refined, hydrogen atoms were treated using appropriate riding models, goodness of fit = 1.069 for observed reflections, final residual values R1(F) = 0.0376 wR(F2) = 0.0976 for observed reflections .CCDC 883509 Crystal data for compound 6.42 : white crystal ( rods ), dimensions 0. 55 x 0. 29 x 0. 26 mm, crystal system o rthorhombic space group P2(1)2(1)2(1) Z = 4, a = 5.9246(9) b = 11.7114(19) c = 16.898(3) 90.00 V = 1172.5(3) 3 1.395 g cm 3 T = 100 31.73 radiation Mo scans with CCD area

PAGE 104

104 detector, covering a whole sphere in reciprocal space, 8626 reflections measured, 2124 unique (R int = 0.0554), 2045 intensities were corrected for Lorentz and polarization effects, an empirical absorption correction was applied using SADABS22 based on the Laue symmetry of the reciprocal space m = 0.099 mm 1 Tmin = 0.6747 Tmax = 0.7463 structure solved by directmeth ods and refined against F2 with a Full matrix least squares algorithmusing the SHELXL 97 software package, 163 parameters refined, hydrogen atoms were treated using appropriate riding models, goodness of fit = 1.071 for observed reflections, final residual values R1(F) = 0.0346 wR(F2) = 0.0888 for observed reflections .CCDC 883510 6.4.4 Kinetic D ata The kinetics for the disappearance of compound 4.27, 4.31 32 were determined by UV spectrophotometry at 20 C in a 10 mm cuvette by following the decrease of t he max = 655.7 nm, 10 mg mL 1 ) The half lives were calculated from the equation of the linear regression line on the concentration versus time plot. The extinction coefficient ( ) was determined prior to each set as the tenth of the slope of the linear regression line of the concentration versus absorbance plot. Samples were measured for their absorbance at three known concentrations. Concentrations were calculated using the Beer Lambert law (A= cl, where A is the absorbance, is the extinction coefficient, c is the concentration in mg/mL, and l is the length of the cuvette in mm) and then normalized. The first order rate constant was determined as the slope of the linear regression line on the natural log versus time plot.

PAGE 105

105 Ki netic data for the disappearance of 4.27 in different solvents Table 6 5. Data for the determination of the extinction coefficient in methanol Concentration (mg/mL) Absorbance (A) 0.008685 0.16395 0.002606 0.04926 0.000782 0.01723 0.000235 0.00492 Figure 6 1 2 Concentration versus absorbance plot for the calculation of the extinction coefficient in methanol Table 6 6. Data for the determination of the rate constant (k obs ) and half life in methanol Time (min) Absorbance Concentration (mg/mL) Normali zed concentration ln(c) 0 0.16395 0.008759 1 0 15 0.15605 0.008337 0.951815 0.04939 45 0.15068 0.008050 0.919061 0.08440 75 0.13869 0.007409 0.845929 0.16732 105 0.13019 0.006955 0.794084 0.23057 120 0.12498 0.006677 0.762306 0.27141 135 0.1188 1 0.006347 0.724672 0.32204 150 0.11217 0.005993 0.684172 0.37955 165 0.10953 0.005852 0.668070 0.40336 195 0.10142 0.005418 0.618603 0.48029 210 0.09619 0.005139 0.586703 0.53324 225 0.09265 0.004950 0.565111 0.57073 140 0.08806 0.004705 0.537 115 0.62154 255 0.08413 0.004495 0.513144 0.66720 270 0.08089 0.004322 0.493382 0.70647 285 0.07407 0.003957 0.451778 0.79456 300 0.07301 0.003901 0.445319 0.80897

PAGE 106

106 Table 6 6. Continued Time (min) Absorbance Concentration (mg/mL) Normalized conc entration In(c) 315 0.06933 0.003704 0.422873 0.86068 330 0.06569 0.003509 0.400671 0.91461 345 0.06179 0.003301 0.376877 0.97584 360 0.05969 0.003189 0.364074 1.01040 375 0.05591 0.002987 0.341019 1.07582 390 0.05208 0.002782 0.317658 1.14678 405 420 0.04871 0.04648 0.002602 0.002483 0.297103 0.283501 1.21368 1.26054 Figure 6 1 3 Time versus normalized concentration plot for the calculation of the half live in methanol

PAGE 107

107 Figure 6 1 4 Time versus ln(c) plot for the calculation of the rate constant (k obs ) in methanol Table 6 7. Data for the determination of the extinction coefficient in dichloromethane Concentration (mg/mL) Absorbance 0.008685 0.20743 0.002606 0.05714 0.000782 0.01791 0.000235 0.00603 Figure 6 1 5 Concentration versus absorbance plot for the calculation of the extinction coefficient in dichloromethane

PAGE 108

108 Table 6 8. Data for the determination of the rate constant (k obs ) and half life in dichloromethane Time (min) A bsorbance C oncentration (mg/mL) Normalized c oncentrat ion l n ( c ) 0 0.20743 0.008662 1 0 30 0.19776 0.008258 0.953382 0.04774 45 0.19421 0.008110 0.936268 0.06585 60 0.18993 0.007931 0.915629 0.08814 75 0.18656 0.007791 0.899388 0.10604 90 0.18284 0.007635 0.881454 0.12618 105 0.17642 0.007367 0.850504 0.16193 135 0.16980 0.007091 0.818589 0.20017 150 0.16807 0.007018 0.810249 0.21041 165 0.16182 0.006757 0.780119 0.24831 180 0.16012 0.006686 0.771923 0.25887 195 0.15674 0.006545 0.755628 0.28021 210 0.15276 0.006379 0.736441 0.30593 225 0.14919 0.006230 0.719231 0.32957 240 0.14952 0.006244 0.720821 0.32736 255 0.14394 0.006011 0.693921 0.36540 270 0.14244 0.005948 0.686689 0.37587 285 0.13725 0.005731 0.661669 0.41299 300 0.13427 0.005607 0.647303 0.43494 315 0.13222 0.005521 0.637420 0.45033 330 0.12863 0.005371 0.620113 0.47785 345 0.12607 0.005265 0.607771 0.49796 360 0.12416 0.005185 0.598563 0.51322 390 0.11835 0.004942 0.570554 0.56115 405 0.11438 0.004776 0.551415 0.59527 420 0.113 67 0.004747 0.547992 0.60149 435 0.11054 0.004616 0.532903 0.62942 450 0.10858 0.004534 0.523454 0.64731 465 0.10575 0.004416 0.509811 0.67372 480 0.10425 0.004353 0.502579 0.68800 495 0.10172 0.004248 0.490382 0.71257 510 0.10128 0.00422 9 0.488261 0.71690 525 0.09772 0.004081 0.471099 0.75269 540 0.09450 0.003946 0.455575 0.78619

PAGE 109

109 Figure 6 1 6 Time versus normalized concentration plot for the calculation of the half live in dichloromethane Figure 6 1 7 Time versus ln(c) plot for the calculation of the rate constant (k obs ) in dichloromethane Table 6 9. Data for the determination of the extinction coefficient in acetonitrile Concentration (mg/mL) Absorbance 0.008685 0.18831 0.002606 0.05548 0.000782 0.01628 0.000235 0.00609

PAGE 110

110 Figure 6 1 8 Concentration versus absorbance plot for the calculation of the extinction coefficient in acetonitrile Table 6 10. Data for the determination of the rate constant (k obs ) and half life in acetonitrile Time (min) A bsorbance C oncentration (mg /mL) Normalized c oncentration l n ( c ) 0 0.18831 0.008693 1 0 30 0.17524 0.008090 0.930593 0.07193 45 0.17000 0.007848 0.902767 0.10229 60 0.16527 0.007629 0.877649 0.13051 75 0.15757 0.007274 0.836759 0.17822 90 0.15326 0.007075 0.813871 0.2 0595 105 0.14976 0.006913 0.795284 0.22906 135 0.13966 0.006447 0.741649 0.29888 150 0.13851 0.006394 0.735542 0.30715 165 0.13365 0.006170 0.709734 0.34287 180 0.13088 0.006042 0.695024 0.36381 195 0.12680 0.005854 0.673358 0.39548 210 0.12320 0.005687 0.654240 0.42428 225 0.11949 0.005516 0.634539 0.45486 240 0.11697 0.005400 0.621157 0.47617 255 0.11324 0.005228 0.601349 0.50858 270 0.10925 0.005043 0.580160 0.54445 285 0.10626 0.004905 0.564282 0.57220 300 0.10220 0. 004718 0.542722 0.61116 315 0.09962 0.004599 0.529021 0.63673 330 0.09590 0.004427 0.509267 0.67478 345 0.09368 0.004325 0.497478 0.69820 360 0.09077 0.004190 0.482024 0.72976 390 0.08342 0.003851 0.442993 0.81420 405 0.08233 0.003801 0. 437199 0.82737 420 0.08054 0.003718 0.427699 0.84934 435 0.07852 0.003625 0.416972 0.87474

PAGE 111

111 Table 6 10. Continued Time (min) Absorbance Concentration (mg/mL) Normalized concentration ln(c) 450 0.07510 0.003467 0.398816 0.91926 465 0.07243 0.003 344 0.384626 0.95548 480 0.06997 0.003230 0.371568 0.99002 Figure 6 1 9 Time versus normalized concentration plot for the calculation of the half live in acetonitrile Figure 6 20 Time versus ln(c) plot for the calculation of the rate constant ( k obs ) in acetonitrile

PAGE 112

112 Table 6 1 1 Data for the determination of the extinction coefficient in acetonitrile:water 7:3 Concentration (mg/mL) Absorbance 0.008685 0.1 9768 0.002606 0.0 6251 0.000782 0.0 2074 0.000235 0.00 674 Figure 6 2 1 Concentration ver sus absorbance plot for the calculation of the extinction coefficient in acetonitrile:water 7:3 Table 6 1 2 Data for the determination of the rate constant (k obs ) and half life in acetonitrile:water 7:3 Time (min) A bsorbance C oncentration (mg/mL) Normalize d c oncentration l n ( c ) 0 0.19768 0.008791 1 0 15 0.19409 0.008631 0.981839 0.01833 30 0.18903 0.008406 0.956242 0.04474 45 0.18550 0.008249 0.938385 0.06359 60 0.18136 0.008065 0.917442 0.08617 75 0.17990 0.008000 0.910057 0.09425 90 0.173 05 0.007696 0.875405 0.13307 105 0.16796 0.007469 0.849656 0.16292 120 0.16342 0.007267 0.826690 0.19033 135 0.15942 0.007089 0.806455 0.21511 150 0.15626 0.006949 0.790469 0.23513 165 0.15239 0.006777 0.770892 0.26021 180 0.14852 0.00660 5 0.751315 0.28593 195 0.14671 0.006524 0.742159 0.29819 210 0.13925 0.006192 0.704421 0.35038 225 0.13790 0.006132 0.697592 0.36012 240 0.13360 0.005941 0.675840 0.39180 255 0.12898 0.005736 0.652469 0.42699

PAGE 113

113 Table 6 12 Continued Time (mi n) Absorbance Concentration (mg/mL) Normalized concentration ln(c) 300 0.11661 0.005186 0.589893 0.52781 315 0.11393 0.005066 0.576335 0.55107 330 0.11035 0.004907 0.558225 0.58299 345 0.10760 0.004785 0.544314 0.60823 360 0.10453 0.004648 0 .528784 0.63718 375 0.10191 0.004532 0.515530 0.66256 390 0.09587 0.004263 0.484976 0.72366 405 0.09512 0.004230 0.481182 0.73151 420 0.09245 0.004111 0.467675 0.75998 Figure 6 2 2 Time versus normalized concentration plot for the calculat ion of the half live in acetonitrile:water 7:3

PAGE 114

114 Figure 6 2 3 Time versus ln(c) plot for the calculation of the rate constant (k obs ) in acetonitrile:water 7:3 Kinetic data for the disappearance of 4.27 at different concentration in acetonitrile Table 6 1 3 Data for the determination of the extinction coefficient in acetonitrile Concentration (mg/mL) Absorbance 0.004343 0.09507 0.008685 0.18715 0.017371 0.381769 Figure 6 2 4 Concentration versus absorbance plot for the calculation of the extinction c oefficient in acetonitrile

PAGE 115

115 Table 6 1 4 Data for the determination of the half life in acetonitrile at 1mg/mL concentration Time (min) A bsorbance C oncentration (mg/mL) Normalized concentration 0 0.09507 0.004309 1 15 0.09372 0.004248 0.98581 0 30 0.0879 4 0.003986 0.925003 45 0.08395 0.003805 0.883034 60 0.0821 8 0.003725 0.864405 75 0.07926 0.003592 0.833701 90 0.07616 0.003452 0.801094 105 0.07235 0.003279 0.761018 120 0.0698 0 0.003164 0.734196 135 0.06751 0.00306 0 0.710119 150 0.06533 0. 002961 0.687178 165 0.0619 2 0.002806 0.651299 180 0.06191 0.002806 0.651204 195 0.05951 0.002697 0.62596 0 210 0.05693 0.00258 0 0.598822 225 0.05426 0.002459 0.570737 240 0.05107 0.002315 0.537183 255 0.05054 0.002291 0.531608 270 0.04804 0. 002177 0.505312 285 0.04585 0.002078 0.482276 300 0.04449 0.002016 0.467971 315 0.04266 0.001934 0.448722 330 0.04131 0.001872 0.434522 345 0.03987 0.001807 0.419375 360 0.0375 0 0.0017 00 0.394446 375 0.03632 0.001646 0.382034 390 0.03495 0. 001584 0.367624 405 0.03366 0.001526 0.354055

PAGE 116

116 Figure 6 2 5 Time versus normalized concentration plot for the calculation of the half live in acetonitrile at 1 mg/mL concentration Table 6 1 5 Data for the determination of the half life in acetonitri le at 2 mg/mL concentration Time (min) A bsorbance C oncentration (mg/mL) Normalized concentration 0 0.18715 0.008483 1 15 0.18290 0.008290 0.977291 30 0.17787 0.008062 0.950414 45 0.17241 0.007814 0.921240 60 0.16850 0.007637 0.900347 75 0.16499 0.007478 0.881592 90 0.16138 0.007315 0.862303 105 0.15660 0.007098 0.836762 120 0.15269 0.006921 0.815870 135 0.14948 0.006775 0.798718 150 0.14634 0.006633 0.781940 165 0.14300 0.006481 0.764093 180 0.13867 0.006285 0.740956 195 0.13548 0 .006141 0.723911 210 0.13143 0.005957 0.702271 225 0.12705 0.005759 0.678867 240 0.12347 0.005596 0.659738 255 0.12142 0.005503 0.648784 270 0.11723 0.005313 0.626396

PAGE 117

117 Table 6 15. Continued Time (min) Absorbance Concentration (mg/mL) Normalize d concentration 285 0.11374 0.005155 0.607753 300 0.11056 0.005011 0.590756 315 0.10711 0.004855 0.572322 330 0.10438 0.004731 0.557734 345 0.10137 0.004595 0.541651 360 0.09747 0.004418 0.520812 375 0.09435 0.004276 0.504136 390 0.09158 0.0 04151 0.489340 405 0.08846 0.004009 0.472669 420 0.08472 0.003840 0.452680 435 0.08265 0.003746 0.441624 450 0.07996 0.003624 0.427251 Figure 6 2 6 Time versus normalized concentration plot for the calculation of the half live in acetonitrile at 2 mg/mL concentration Table 6 1 6 Data for the determination of the half life in acetonitrile at 4 mg/mL concentration Time (min) Absorbance Concentration (mg/mL) Normalized concentration 0 0.38177 0.017304 1 15 0.37685 0.017081 0.987115 30 0.37004 0.016772 0.969277 45 0.36169 0.016394 0.947405

PAGE 118

118 Table 6 16. Continued Time (min) Absorbance Concentration (mg/mL) Normalized concentration 60 0.35787 0.016220 0.937399 75 0.35259 0.015981 0.923569 90 0.34942 0.015837 0.915266 105 0.33894 0.015 362 0.887814 120 0.33355 0.015118 0.873696 135 0.32824 0.014877 0.859787 150 0.32379 0.014676 0.848131 165 0.31814 0.014420 0.833331 180 0.31147 0.014117 0.815860 195 0.30794 0.013957 0.806613 210 0.30220 0.013697 0.791578 225 0.29476 0.013 360 0.772090 240 0.28868 0.013084 0.756164 255 0.28682 0.013000 0.751292 270 0.27855 0.012625 0.729630 285 0.27463 0.012448 0.719362 300 0.26901 0.012193 0.704641 315 0.26463 0.011994 0.693168 330 0.25966 0.011769 0.680150 345 0.25253 0.011 446 0.661473 360 0.24629 0.011163 0.645128 375 0.24032 0.010892 0.629491 390 0.23692 0.010738 0.620585 405 0.23156 0.010495 0.606545 420 0.22634 0.010259 0.592872 435 0.22124 0.010028 0.579513 450 0.21724 0.009846 0.569035 465 0.21071 0.009 550 0.551931 480 0.20408 0.009250 0.534564 495 0.19889 0.009015 0.520969 510 0.19327 0.008760 0.506249 525 0.18658 0.008457 0.488725 540 0.18102 0.008205 0.474161 555 0.17566 0.007962 0.460121 570 0.17328 0.007854 0.453887

PAGE 119

119 Figure 6 2 7 T ime versus normalized concentration plot for the calculation of the half live in acetonitrile at 4 mg/mL concentration Kinetic data for the disappearance of 4.31 and 4.32 in dichloromethane Table 6 1 7 Data for the determination of the extinction coeffici ent for 4.31 in dichloromethane Concentration (mg/mL) Absorbance 0.008938 0.12694 0.002681 0.03468 0.000804 0.01119 0.000241 0.00324 Figure 6 2 8 Concentration versus absorbance plot for the calculation of the extinction coefficient for 4.31 in dic hloromethane

PAGE 120

120 Table 6 1 8 Data for the determination of the half life for 4.31 in dichloromethane Time (min) A bsorbance C oncentration (mg/mL) Normalized concentration 0 0.12694 0.008902 1 15 0.11956 0.008384 0.941862 30 0.11454 0.008032 0.902316 45 0.10923 0.007660 0.860485 60 0.10317 0.007235 0.812746 75 0.09814 0.006882 0.773121 90 0.09451 0.006628 0.744525 105 0.09044 0.006342 0.712463 120 0.08348 0.005854 0.657626 135 0.08101 0.005681 0.638176 150 0.07795 0.005466 0.614070 165 0.0 7571 0.005309 0.596424 180 0.07094 0.004975 0.558847 195 0.06910 0.004846 0.544352 210 0.06556 0.004597 0.516464 225 0.06345 0.004450 0.499842 240 0.05969 0.004186 0.470222 255 0.05801 0.004068 0.456988 270 0.05562 0.003900 0.438160 285 0.0 5102 0.003578 0.401922 Figure 6 2 9 Time versus normalized concentration plot for the calculation of the half live for 4.31 in dichloromethane

PAGE 121

121 Table 6 1 9 Data for the determination of the extinction coefficient for 4.32 in dichloromethane Concentrati on (mg/mL) Absorbance 0.008814 0.16542 0.002644 0.04848 0.000793 0.01453 0.000238 0.0048 Figure 6 30 Concentration versus absorbance plot for the calculation of the extinction coefficient for 4.32 in dichloromethane Table 6 20 Data for the determ ination of the half life for 4.32 in dichloromethane Time (min) A bsorbance Concentration (mg/mL) Normalized concentration 0 0.16542 0.008809 1 15 0.15775 0.008401 0.953633 30 0.15167 0.008077 0.916878 45 0.14506 0.007725 0.876919 60 0.13762 0.0073 29 0.831943 75 0.13228 0.007044 0.799661 90 0.12682 0.006754 0.766655 105 0.12182 0.006487 0.736428 120 0.11574 0.006164 0.699674 135 0.1133 0 0.006034 0.684923 150 0.10817 0.00576 0 0.653911 165 0.1041 0 0.005544 0.629307 180 0.10033 0.005343 0.606517 195 0.09653 0.005141 0.583545 210 0.0919 8 0.004898 0.556033 225 0.08785 0.004678 0.531072 240 0.08438 0.004494 0.510096 255 0.08165 0.004348 0.493592

PAGE 122

122 Table 6 20. Continued Time (min) Absorbance Concentration (mg/mL) Normalized conce ntration 270 0.07766 0.004136 0.469472 285 0.07162 0.003814 0.432959 Figure 6 3 1 Time versus normalized concentration plot for the calculation of the half live for 4.32 in dichloromethane

PAGE 123

123 CHAPTER 7 SUMMARY OF ACHIEV E MENTS Synthetic organic chemis try plays an important role in the fields of material science, pharmaceuticals, cosmetics, food chemistry, and agricultures. The present work describes the synthesis of small molecular libraries of biologically important molecules utilizing the standard be nzotriazole methodology and the synthesis of heterocycles which can be used in material sciences. Chapter 1 gives a general overview of the benzotriazole methodology focusing on benzotriazolides. Chapter 2 presents the results of the use of benzotriazole i n order to achieve the synthesis of dye labeled nucleosides and Chapter 3 the amino acid conjugates of quinolone antibiotics. The moderate reactivity of acyl benzotriazoles compare to acyl chlorides allows the synthesis to proceed without the use of protec ting groups. Chapter 4 summerizes the results of the effort made for the synthesis of unsymmetric diketopyrrolopyrrole dyes. However, we were not able to achieve the goal of the project, a new aspect of the benzotriazole and imidazole mediated synthesis w ere shown. Chapter 5 describes the progress toward the synthesis of quinoxalino ligands which can be used as scavengers for the purification of metal catalyzed reactions. However, despite being an incomplete work it gives a prospective towards synthesis of aza crown macrocycles. In Chapter 6 a new class of geminally substituted nitroso compounds, benzotriazoyl nitroso derivatives are presented. These compounds display unique behavior compared to related nitroso compounds bearing a geminal electron

PAGE 124

124 withdrawing group. An unexpected, spontaneous oxidation to the nitro analog was observed in sol ution and verified through experimental characterization and computational rationale. Kinetic measurements on the conversion of the C nitroso moiety to the C nitro in the product are the major features of this work

PAGE 125

125 LIST OF REFERENCES The reference citati on system employed throughout this research report is from (Eds. Katritzky, A. R.; Rees, C. W.; Scriven, E.). Each time a reference is cited, a number letter code is designated to the corresponding reference with the first two or four if the reference is er indicating the year followed by the letter code of the journal and the page number in the end. REFERENCES [47CCCC292 ] Wichterle, O Coll Czechoslovak Chem. Commun. 1947 12 292 304 [49JCS1260] Crowther, A. F.; Curd, F. H. S.; Davey, D. G.; Stacey, G. J. J. Chem. Soc., 1949, 1260 1262 [54SCI989] Davis, D. Science 1954 120 989. [63JACS64 ] Belleau, B.; Au Young, Y. K. J. Am. Chem. Soc., 1963 85 64 71 [ 67JACS5780 ] MacDermott, T. E.; Busch, D. H. J. Am. Chem. Soc., 1967, 89, 5780 5784 [71JACS3056] Leon ard, N. J.; Playtis, A. J.; Skoog, F.; Schmitz, R. Y. J. Am. Chem. Soc., 1971 93, 3056 3058 [73JCSDT863] Curtis, N. F. J. Chem. Soc. Dalton Trans., 1973, 869 866 [74JACS2268] Richman, J. E.; Atkins, T. J. J. Am. Chem. Soc., 1974, 2268 2270 [75JACS2497] De ll, A.; William, D. H.; Morris, H. R.; Smith, G. A.; Feeney, J.; Roberts, G. C. K. J. Am. Chem. Soc 1975 97 2497 [ 76AAC20 ] Rohlfing S R ; Gerster J R ; Kvam D Antimicrobial A gents and C hemotherapy 1976 10 20 2 4 [76CR625] Rao, Y. S. Chem. Rev., 1976, 76, 625 694 [76JHC13] Komin, A. P.; Carmack, M. J. Het. Chem., 1976, 13, 13 22

PAGE 126

126 [76TL4339] Tabushi, I.; Okino, H.; Kuroda, Y. Tetrahedron Lett., 1976, 48, 4339 4342 [ 77JAC411 ] Mardh, P. A.; Colleen, S.; Andersson, K. E J. Antimicrob. Chemother 1977 3 411 4 16 [79CL287] Makino, T.; Hata, K.; Saburi, M.; Yoshikawa, S. Chem. Lett., 1979, 287 290 [ 80JACS2167 ] Heesemann, J. J. Am. Chem. Soc. 1980 102 2167 2176 [ 80JACS2176 ] Heesemann, J. J. Am. Chem. Soc. 1980 102 2176 2181 [ 84AAC633 ] Barry A L ; Jones R N ; Thornsberry C ; Ayers L. W.; Gerlach, E. H.; Sommers, H. M. Antimicrob. A gents and C hemotherapy 1984 25 633 63 7 [84TL5091] Iida, H.; Watanabe, Y.; Kibayashi, C. Tetrahedron Lett., 1984 25 5091 5094 [EP0163609A2] Rochat, A. C.; Iqbal, A. ; Pfenninger, J.; Cassar, L. 1985 Patent Appl. EP0163609A2 [ 85FR2564832 ] Laruelle, C.; Lepant, M.; Raynier, B. 1985, Patent Appl FR 2564832 [ 85HU36483 ] Pongracz, K.; Frank, J.; Kulcsar, G.; Medzihradszky, K.; Nadasi L. 1985, Patent Appl. HU36483 [ 85HU368 42 ] Pongracz, K.; Frank, J.; Kulcsar, G.; Medzihradszky, K.; Nadasi L.; Szokan, G. 1985, Patent Appl. HU36842 [ 85JCSPTI883] Corrie, J. E. T.; Kirby, G. W.; Mackinnon, J. W. M. J. Chem. Soc. Perkin Trans. I, 1985, 883 886 [ 85JP56053679 ] K azuo K. ; M ineharu S. ; K ikuo W. ; S higeru Y. 1985, Patent Appl. JP 56053679 [ 85DECR331 ] Galante, D.; Pennucci, C.; Esposito, S.; Barba, Drugs under Experimental and Clinical Research 1985 11 331 34 4 [86CC1158] K imura E.; Fujioka H.; Kodama, M. J. Chem. Soc., Chem. Comm un. 1986 1158 1159 [86PAC1445] Hancock, R. D. Pure & Appl. Chem., 1986, 58, 1445 1452 [ 87 DE3525109A1] Frustenwerth, H. 1987 Patent Appl. DE3525109A1

PAGE 127

127 [87AJC1441] Lawrance, G. A.; Rossignoli, M.; Skelton, B. W.; White, A. H. Aust. J. Chem., 1987, 40, 1441 1449 [ 87KFZ692 ] Leonova, T. S.; Padeiskaya, E. N.; Yashunskii, V. G Khimiko Farmatsevticheskii Zhurnal, 1987 21 692 696 [ 88ACIE1437 ] Gompper, R.; Wagner H. U. Angew. Chem. Int. Ed ., 1988 27 1437 1455 [88H2481] Sakata, G.; Makino, K.; Karasawa, Y. He terocycles 1988 27 2481 [ 89EU304087 ] Sanchez, J. P. 1989, Patent Appl. EU 304087 [89JOC2990] Chavez, F.; Sherry, A. D. J. Org. Chem., 1989, 54, 2990 2992 [ 89NAR7643 ] Roget, A.; Bazin, H.; Teoule, R. Nucleic Acids Res 1989, 17 7643 7651 [89PAC1619] Bra dshaw, J. S.; Krakowiak, K. E.; Tarbet, B. J,; Bruening, R. L.; Biernat, J. F.; Bochenska, M.; Izatt, R. M.; Christensen, J. J. Pure & Appl. Chem., 1989, 61, 1619 1624 [89TL3983] Tsukube, H.; Yamashita, K.; Iwachido, T.; Zenki, M. Tetrahedron Lett., 1989, 30, 3983 3986 [89TL4125] Dietrich, B.; Lehn, J. M.; Guilhem, J.; Pascard, C. Tetrahedron Lett., 1989, 30, 4125 4128 [90EP0382582] Parker, D.; Eaton, M. A. W. 1990, Patent Appl. EP0382582 [90JMC2240] Sarges, R.; Howard, H. R.; Browne, R. G.; Lebel, L. A.; S eymour, P. A.; Koe, B. K. J. Med. Chem., 1990, 33, 2240 2254 [90JOC3364] Krakowiak, K. E.; Bradshaw, J. S.; Izatt, R. M. J. Org. Chem., 1990, 55, 3364 3368 [ 90TL991 ] Oppolzer, W.; Tamura, O. Tetrahedron Lett., 1990, 31 991 994 [ 91CB1809 ] Katritzky, A. R.; Lan, X.; Lam, J. N. Chem. Ber. 1991 124 1809 1812 [ 91EMB57] Mundy, C. R.; Cunningham, M. W.; Read, C. A. ; Brown T. A. Essential Molecular Biology. A practical Approach. Vol. II. Oxford University Press, New York, USA, 1991, 57 110

PAGE 128

128 [91JOC4904] Qian, L.; Sun, Z.; Mertes, M. P.; Mertes, K. B. J. Org. Chem., 1991, 56, 4904 4907 [91T2683] Katritzky, A. R.; Rachwal, S.; Hitchings, G. J. Tetrahedron 1991 47 2683 [92JACS1499] McCarrick, M. A.; Wu, Y. D.; Houk, K. N. J. Am. Chem. Soc., 1992 114 1499 1500 [ 9 2JACS5900] Oppolzer, W.; Tamura, O.; Sundarababu, G.; Signer, M. J. Am. Chem. Soc., 1992 114 5900 5902 [ 92JBC13150 ] Elsea, S. H.; Osheroff, N.; Nitiss, J. L. J. Biol. Chem., 1992, 267, 13150 13153 [ 92P57 ] Kohli, D. V.; Uppadhyay, R. K.; Saraf, S. K.; Vis hwakarma, K. K Pharmazie 1992 47 57 59 [92T7817] Katritzky, A. R.; Shobana, N.; Pernak, J.; Afhdi, A. S.; Fan, W. G. Tetrahedron 1992 48 7817 7819 [93book537] Bradshow, J. S.; Krakowiak, K. E.; Izatt, R. M. Aza crown Macrocycles, John Wiley & sons, I nc. 1993 539 692 [ 93BC105 ] Mujumdar, R. B.; Ernst, L. A.; Mujumdar, S. R.; Lewis, C. J.; Waggoner, A. S. Bioconjugate Chem ., 1993 4 105 111 [94CSR363] Katritzky A. R.; Lan X. Chem. Soc. Rev. 1994 363. [94S 1107] Streith, J.; Defoin, A. Synthesis 199 4 11 1107 1117 [95JMC4488] Monge, A.; Martinez Crespo, F. J.; Cerain, A. L.; Palop, J. A.; Narro, S.; Senador, V.; Martin, A.; Sainz, Y.; Gonzalez, M.; Hamilton, E.; Barker, A. J. J. Med. Chem., 1995, 38, 4488 4494 [ 95MCP145 ] Mansfield, E. S.; Worley, J. M.; McKenzie, S. E.; Surrey, S.; Rappaport, E.; Fortina, P. Mol Cell Probes 1995, 9 145 156 [95SC2319] Villemin, D.; Martin, B. Synth. Commun., 1995 25, 2319 2326 [ 96BC356 ] Mujumdar, S. R.; Mujumdar, R. B.; Grant, C. M.; Waggoner, A. S. Bioconjugate Ch em ., 1996 7 356 362 [ 96JME23 ] Bustin, S. A. J. Mol. Endocrinol. 1996 29 23 39

PAGE 129

129 [96JOC1047 ] Glaser, R.; Murmann, R. K.; Barnes, C. L. J. Org. Chem. 1996 61 1047 1049 [96JOC1624] Katritzky, A. R.; Li, J. J. Org. Chem., 1996, 61, 1624 1628 [ 96P30 ] Abou l Fadl T; Fouad E. A. Pharmazie 1996 51 30 33 [ 96TL637 ] Yamana, K.; Yoshikawa, A.; Nakano, H. Tetrahedron Lett. 1996 37 637 640 [97IOP9] Herbst, W.; Hunger, K. Ind. Org. Pigments, 1997, VCH Wiley, 489 496 [97JOC4148] Katritzky, A. R.; Fali, C. N.; Li, J. J. Org. Chem. 1997 62 4148 [97TL5269] Wuckelt, J.; Doring, M.; Langer, P.; Gorls, H.; Beckert, R. Tetrahedron Letters, 1997, 38, 5269 5272 [ 98BBA29 ] Levine, C., H. Hiasa, and K. Marians. Biochim. Biophys. Acta 1998 29 43 [ 98BBA178 ] Matsuo, T. Bioc hem Biophys Acta 1998, 178 184 [ 98BJ9] Yoshida, H.; Kondratenko, N.; Green, S.; Steinberg, D.; Quehenberger, O. Biochem. J., 1998, 334. 9 13 [98CC2251 ] Hall, A.; Bailey, P. D.; Rees, D. C.; Wightman, R. H. Chem. Commun., 1998 2251 2252 [98CR409] Katritzk y, A. R.; Lan, X.; Yang, J. Z.; Denisko, O. V. Chem. Rev. 1998 98 409 [ 98TL9015 ] Asanuma, H.; Ito, T.; Komiyama, M. Tetrahedron Lett. 1998 39 9015 9018 [98S153] Katritzky, A. R.; Levell, J. R.; Pleynet, D. P. M. Synthesis, 1998, 153 157 [98T1317 ] Vog t, P. F.; Miller, M. J. Tetrahedron 1998 54 1317 1319 [ 99JMC4479 ] McGuigan, C.; Yarnold, C. J.; Jones, G.; Velazquez, S.; Barucki, H.; Brancale, A.; Andrei, G.; Snoeck, R.; De Clercq, E.; Balzarini, J. J. Med. Chem. 1999 42 4479 4484 [99P808] El Hawa sh, S. A.; Habib, N. S.; Fanaki, N. H. Pharmazie, 1999, 54, 808 815

PAGE 130

130 [99T:A2165] Faitg, T.; Souli, J.; Lallemand, J. Y.; Ricard, L. Tetrahedron: Asymmetry 1999 10, 2165 2174 [ 00WO027813 ] Wilchek, M.; Bayer, E. A.; Hofstetter, H.; Morpurgo, M. 2000, Paten t Appl. WO027813 [ 00BMCL1215 ] Brancale, A.; McGuigan, C.; Andrei, G.; Snoeck, R.; De Clercq, E.; Balzarini, J. Bioorg. Med. Chem. Lett. 2000 10 1215 1217 [ 00JCSPTI329] Hall, A.; Bailey, P. D.; Rees, D. C.; Rosair, G. M.; Wightman, R. H. J. Chem. Soc., P erkin Trans. 1, 2000 329 343 [ 00EJOC211 ] Trvisiol, E.; Defrancq, E.; Lhomme, J.; Laayoun, A.; Cros, P. Eur. J. Org. Chem. 2000 211 217 [00JOC729] Langer, P.; Wuckelt, J.; Doring, M. J. Org. Chem., 2000, 65, 729 734 [ 00JOC2959 ] Harwood, E. A.; Hopkins, P. B.; Sigurdsson, S. T. J. Org. Chem. 2000 65 2959 2964 [00JOC8210] Katritzky, A. R.; He, H. Y.; Suzuki, K. J. Org. Chem. 2000 65 8210 8213 [ 00OL227 ] Wang, Z.; Rizzo, C. J. Org. Lett. 2000 2 227 230 [00PR469] Di Stilo, A.; Medana, C.; Ferrarotti, B.; Gasco, A. L.; Ghigo, D.; Bosia, A.; Martorana, P. A.; Gasco, A. Pharmacol. Res., 2000 41 469 474 [ 00S1624 ] Ichimura, K.; Oh, S. K.; Nakagawa, M. Science 2000 288 1624 1626 [00S 2029] Katritzky, A. R.; Fang, Y.; Donkor, A.; Xu, J. Synthesis 2000 2029 [ 01ACIE2671 ] Asanuma, H.; Takarada, T.; Yoshida, T.; Tamaru, D.; Liang, X.; Komiyama M. Angew. Chem. Int. Ed. 2001 40 2671 2673 [ 01CC1002 ] Graham, D.; Brown, R.; Smith, E. Chem Comm 2001, 1002 1003 [01JMC2238] Dailey, S.; Feast, W. J.; Peace, R. J .; Sage, I. C.; Till, S.; Wood, E. L. J. Mater. Chem 2001 11 2238 2240 [01JOC5192 ] Leach, A. G.; Houk, K. N. J. Org. Chem., 2001, 66, 5192 5200

PAGE 131

131 [ 01JOC5601 ] Katritzky, A. R.; Huang, T. B.; Steel, P. J. J. Org. Chem. 2001 66 5601 5605 [01TL5897] Iwasa, S.; Tajima, K.; Tsushima, S.; Nishiyama, H. Tetrahedron Lett 200 1 42 5897 5899 [ 01TL8115 ] Wu, Z.; Ede, N. J. Tetrahedron Lett 200 1 42 8115 [ 02CMI214 ] Critchley, I. A.; Jones, M. E.; Heinze, P. D.; Hubbard, D.; Engler, H. D.; Evangelista, A. T.; Th ornsberry, C.; Karlowsky, J. A.; Sahm, D. F. Clinical Microbiology and Infection 2002 8 214 216 [ 02JACS9674 ] Anderson, R. D.; Zhou, J.; Hecht, S. M. J. Am. Chem. Soc. 2002 124 9674 9675 [ 02JPC6871 ] Domingo, L. R.; Aurell, M. J.; Prez, P.; Contreras, R. J. Phys. Chem 200 2 106 6871 6875 [ 02OL737 ] Bergbreiter, D. E.; Osburn, P. L.; Li, C. Org. Lett. 2002 4 737 740 [02PIAC391] Chakravarty, A. R.; Reddy, P. A. N.; Santra, B. K.; Thomas, A. M. Proc. Indian Acad. Sci., 2002, 114 391 401 [02PNAS7340 ] Shafirovich, V.; Lymar S. V. Prod. Nat. Acad. Sci. 2002 99 ,7340 7345 [ 02PNAS10958] Bartberger, M. D.; Liu, W.; Ford, E.; Miranda, K. M.; Switzer, C.; Fukuto, J. M.; Farmer, P. J.; Wink, D. A.; Houk K. N. Prod. Nat. Acad. Sci. 2002 99 ,10958 10963 [ 02 TL3971 ] Antoniotti, S.; Donach, E. Tetrahedron Lett 200 2 43 3971 [ 03BMCL1635 ] Jefferson, E. A.; Swayze, E. E.; Osgood, S. A.; Miyaji, A.; Risen, L. M.; Blyn, L. B. Bioorg. Med. Chem. Lett 2003 13, 1635 1638 [03CC2286] Raw, S. A.; Wilfred, C. D.; Tayl or, R. J. K. Chem. Commun 2003 18 2286 2288 [03CHC1] Katritzky, A. R.; Ramsden, C. A.; Scriven, E. F. V.; Taylor, R. J. K. Comprehensive Heterocyclic Chemistry 2003 3 1 [03CR4131] Adam, W.; Krebs, O. Chem. Rev., 2003, 103, 4131 4146 [03EJMC791] Jaso, A.; Zarranz, B.; Aldana, I.; Monge, A. Eur. J. Med. Chem., 2003, 38, 791 800

PAGE 132

132 [ 03JAC1 ] Andersson, M. I.; MacGowan, A. P. J. Antimic. Chemother., 2003, 51, 1 11 [ 03JAC1109 ] Ruiz, J J. Antimicrob. Chemother 2003 51, 1109 1117 [03JOC4932] Katritzky, A. R.; Abdel fattah, A. A. A.; Wang, M. J. Org. Chem. 2003 68 4932 4934 [03JOC5720] Katritzky, A. R.; Suzuki, K.; Singh, S. K.; He, H. Y. J. Org. Chem. 2003 68 5720 5723 [ 03OL2445 ] Bergbreiter, D. E.; Li, C. Org. Lett. 2003 5 2445 2447 [ 03PNAS5537 ] Paolo cci, N.; Katori, T.; Champion, H. C.; John, M. E.; Miranda, K. M.; Fukuto, J. M.; Wink, D. A.; Kass D. A. Prod. Nat. Acad. Sci. 2003 100 5537 5542 [ 03S2147 ] Singh, S. K.; Gupta, P.; Duggineni, S.; Kundu, B. Synlett 200 3 2147 2149 [03S2389] Langer, P. ; Helmholz, F.; Schroeder, R. Synlett, 2003, 2389 2391 [03S2795] Katritzky, A. R.; Zhang, Y.; Singh, S. K. Synthesis 2003 3 2795 [ 03TL8571 ] K. Tetrahedron Lett 2003, 44 8571 8575 [04CC23 56] Galli, C.; Gentili, P.; Lanzalunga, O.; Franco, G.; Sapienza, L.; Moro, P. A. Chem. Comm. 2004 2356 [04 BMCL 5565 ] Zeng, B. B.; Huang, J.; Wright, M. W.; King, S. B. Bioorg. Med. Chem. Lett., 2004, 14, 5565 5568 [04OBC1691] Holzberger, A.; Holdt, H. J. ; Kleinpeter, E. Org. Biomol. Chem., 2004 2, 1691 1697 [04OL2449 ] Calvet, G.; Dussaussois, M.; Blanchard, N.; Kouklovsky, C Org. Lett., 2004 6 2449 2451 [ 04OL2595 ] Norikane, Y.; Tamaoki, N. Org. Lett. 2004 6 2595 2598 [ 04S2645 ] Katritzky, A. R.; Suz uki, K.; Singh, S. K. S ynthesis, 200 4 16 2645 2652 [ 05ARKIVOC36 ] Katritzky, A. R.; Shestopalov, A. A.; Suzuki, K. ARKIVOC 2005 7 36 55

PAGE 133

133 [ 05ARPT335] Fukuto J. M.; Switzer C. H.; Miranda K. M.; Wink, D. A. Annu. Rev. Pharmacol. Toxicol. 2005, 45, 335 3 55 [ 05CC1321 ] Kim, S. Y.; Park, K. H.; Chung, Y. K. Chem. Commun 200 5 1321 1323 [ 05CC3514] Yamamoto, H.; Momiyama, N. Chem. Commun., 2005, 3514 3525 [05CCR433 ] Miranda, K. M. Coord. Chem. Rev. 2005 249 433 436 [05CM1860] Thomas, K. R. J.; Velusamy, M .; Lin, J. T.; Chuen, C. H.; Tao, Y. T. Chem. Mater 2005 17 1860 1864 [05CTMC665] King, S. B. Cur. Top. Med. Chem., 2005 5 665 [ 05CR1377 ] Kinbara, K.; Aida, T. Chem. Rev., 2005 105 1377 1400 [ 05OL2169 ] Venkatesh, C.; Singh, B.; Mahata, P. K.; Junjapp a, H. Org. Lett 200 5 7 2169 [ 05S1656 ] Katritzky, A. R.; Suzuki, K.; Wang Z. Synlett 2005 11 1656 1665 [06ARKIVOC16] Heravi, M. M.; Bakhtiari, K.; Tehrani, M. H.; Javadi, N. M.; Oskooie, H. A. ARKIVOC 2006 16 16 24 [06BMCL1753] Hassan, S. Y.; Khatt ab, S. N.; Bekhit, A. A.; Amer, A. Bioorg. Med. Chem. Lett., 2006, 16, 1753 1756 [06BMC6120] Tandon, V. K.; Yadav, D. B.; Maurya, H. K.; Chaturverdi, A. K.; Shukla, P. K. Bioorg. Med. Chem., 2006, 14, 6120 6126 [06DP45] Jaung, J. Y. Dyes and Pigments 2006 71 45 49 [06EJOC1489] El Murr, M. D.; Nowaczyk, S.; Le Gall, T.; Mioskowski, C. Eur. J. Org. Chem., 2006, 6, 1489 1492 [06EJOC2031] Yamamoto, Y.; Yamamoto, H. Eur. J. Org. Chem., 2006 2031 2043 [ 06EJOC2570 ] Domingo, L. R.; Picher, M. T.; Arroyo, P. Eur J. Org. Chem 200 6 6 2570 2580 [06JACS9687] Sha, X.; Isbell, T. S.; Patel, R. P.; Day, C. S.; King, S. B. J. Am. Chem. Soc., 2006 128, 9687 9692 [ 06JACS15596 ] Grossmann, T. N.; Seitz, O. J. Am. Chem. Soc. 2006 128 15596 15597

PAGE 134

134 [06JHC1569] Kuhn, C.; Beckert, R.; Friedrich, M.; Gorls, H. J. Heterocyclic Chem. 2006, 43, 1569 1574 [ 06JOC5897 ] Aparicio, D.; Attanasi, O. A.; Filippone, P.; Ignacio, R.; Lillini, S.; Mantellini, F.; Palacios, F.; Santos, J. M. J. Org. Chem 200 6 71 5897 [ 06JOC9861 ] Katri tzky, A. R.; Khanh, N. B.; Khelashvili, L.; Mohapatra, P. P. J. Org. Chem. 2006 71 9861 9864 [ 06N512 ] Muraoka, T.; Kinbara, K.; Aida, T. Nature 2006 440 512 515 [ 06OL2023 ] Ferguson, C. G.; Bigman, C. S.; Richardson, R. D.; Van Meeteren, L. A.; Moolen aar, W. H.; Prestwich, G. D. Org Lett 2006, 8 2023 2026 [ 06OL2575 ] Rose, T. M.; Prestwich, G. D. Org. Lett. 2006 8 2575 2578 [06S411] Katritzky, A. R.; Angrish, P.; Suzuki, K. Synthesis 2006 411 414 [06S2507] Helmholz, F.; Schroeder, R.; Langer, P. Synthesis, 2006, 2507 2514 [06S3231] Katritzky, A. R.; Tala, S. R.; Singh, S. Synthesis 2006 3231 [ 06ST60 ] Katritzky, A. R.; Angrish, P. Steroids 2006 71 660 669 [ 07US072196 ] Xu, Y.; Wegener, J.; Bibillo, A. 2007, Patent Appl. US 072196 [07WO200700352 0] Oka, H.; Yamamoto, H.; Tanabe, J. 2007, Patent Appl. WO2007003520A1 [07BCSJ59 5 ] Yamamoto, H.; Kawasaki, M. Bull. Chem. Soc. Jpn., 2007 80 595 607 [07BMCL194] Guillon, J.; Forfar, I.; Matsuda, M. M.; Desplat, V.; Saliege, M.; Thiolat, D. Bioorg. Med. C hem. Lett., 2007, 15, 194 210 [ 07ARKIVOC142 ] Katritzky, A. R.; Tao H.; Kirichenko K. A RKIVOC 2007 10 142 151 [ 07BMCL6000 ] Katritzky, A. R.; Angrish, P.; Todadze, E.; Ghiviriga J. Bioorg. Med. Chem. Lett. 2007, 17 6000 6003 [ 07CPL341 ] Domingo, L. R. ; Sez, J. A. ; Prez, P. Chem. Phys. Lett. 2007 438 341 345

PAGE 135

135 [07FRBM482] Lopez, B. E.; Shinyashiki, M.; Han, T. H.; Fukuto, J. M. Free Radical Bio. Med. 2007, 42, 482 491 [07IJHC283] Ganapaty, S.; Ramalingam, P.; Rao, C. B. Ind. J. Het. Chem. 2007 16 283 286 [07JOC5202] de los Santos, J. M.; Ignacio, R,; Aparicio, D.; Palacios, F. Org. Chem. 2007 72 5202 5206 [ 07JOC5794 ] Katritzky, A. R.; Todadze, E.; Angrish, P.; Draghici B. J. Org. Chem. 2007 72 5794 5801 [ 07S3676 ] Katritzky, A. R.; Khelashvili L.; Mohapatra, P. P.; Steel, P. J Synthesis 2007 23 3673 3677 [ 07TL4665 ] Cho, C. S.; Renb, W. X.; Shimb, S. C. Tetrahedron Lett 200 7 4 8 4665 [08CC778] Kumar, A.; Kumar, S.; Saxena, A.; De, A.; Mozumdar, S. Catal. Commun. 2008 778 [ 08CR1588 ] Sjul son, L.; Miesenbck, G. Chem. Rev ., 2008, 5 1588 1602 [08EJOC3279] Astolfi, P. ; Carloni, P.; Damiani, E.; Greci, L.; Marini, M.; Rizzoli, C,; Stipa, P. Eur. J. Org. Chem., 2008, 3279 3285 [ 08JOC4615 ] Domingo, L. R. ; Chamorro, E. ; Prez, P. J. Org. Chem. 2008 73 4615 4624 [ 08JOC5442 ] Katritzky, A. R.; El Gendy, B. E. D. M;. Todadze, E.; Abdel Fattah, A. A. A. J. Org. Chem. 2008 73 5442 5445 [ 08OBC2400 ] Katritzky, A. R.; Chen, Q Y.; Tala, S. R. Org. Biomol. Chem. 2008 6 2400 2404 [08S3071] Bueh rdel, G.; Beckert, R.; Petrlikova, E.; Herzigova, P.; Klimesova, V.; Fleischhauer, J.; Goerls, H. Synthesis, 2008, 3071 3080 [ 09AJPHC1274] Tsuruda, T.; Hatakeyama, K.; Masuyama, H.; Sekita, Y.; Imamura, T.; Asada, Y.; Kitamura K. Am. J. Physiol. Heart Cir c. Physiol. 2009, 297, 1274 1280 [ 09JOC1450] Chakrapani, H.; Bartberger, M. D.; Toone, E. J. J. Org. Chem. 2009 74 1450 1455

PAGE 136

136 [09OL2719 ] Reisz, J. A.; Klorig, E. B.; Wright, M. W.; King, S. B. Org. Lett., 2009, 11, 2719 2721 [ 10CC3788 ] Matsuo, K.; Nakaga wa, H.; Adachi, Y.; Kameda, E.; Tsumoto, H.; Suzuki, T.; Miyata, N. Chem. Comm. 2010 46 3788 [ 10IC6955 ] Inorg. Chem., 2010 49, 6955 6966 [10JACS9774] Ellis, W. C.; Tran, C. T.; Roy, R.; Rusten, M.; Fischer, A.; Ryabov, A. D.; Blumberg, B.; Collins, T. J. J. Am. Chem. Soc., 2010, 132, 9774 9781 [ 10JACS16526 ] Andrei, D.; Salmon, D. J.; Donzelli, S.; Wahab, A.; Klose, J. R.; Ci tro, M. L.; Saavedra, J. E.; Wink, D. A.; Miranda, K. M.; Keefer, L. K. J. Am. Chem. Soc., 2010, 132, 16526 16532 [ 10JMST C 49] Monbaliu, J. C.; Dive, G.; Marchand Brynaert, J.; Peeters, D. J. Mol. Struc. Theochem, 2010 959 49 54 [ 10JOC5478 ] Monbaliu, J. C .; Tinant, B.; Marchand Brynaert, J. J. Org. Chem., 2010, 75, 5478 5486 [10PCCP9597] Coote, M. L.; Lin, C. Y.; Beckwith, A. L. J.; Zavitsas, A. A. Phys. Chem. Chem. Phys., 2010 12 9597 9610 [ 10T2969] Calvet, G.; Coote, S. C.; Blanchard, N.; Kouklovsky, C Tetrahedron 2010 66 2969 2980 [10TA1507] Li, H.; Gori, D.; Kouklovsky, C.; Vincent, G. Tetrahedron: Asymmetry, 2010 21 1507 1510 [ 11ARS1637] DuMond, J. F.; King, S. B. Antioxid. Redox Signaling, 2011 14 1637 1648 [ 11IC3262 ] Salmon, D. J.; Torres de Holding, C. L.; Thomas, L.; Peterson, K. V.; Goodman, G. P.; Saavedra, J. E.; Srinivasan, A.; Davies, K. M.; Keefer, L. K.; Miranda, K. M. Inorg. Chem., 2011, 50, 3262 3270 [11IJPTR386] Patidar, A. K.; Jeyakandan, M.; Mobiya, A. K.; Selvam, G. Int. J. Pharm. Thech. Res., 2011, 3, 386 392 [ 11JACS11675 ] Reisz, J. A.; Zink, C. N.; King, S. B. J. Am. Chem. Soc., 2011, 133, 11675 11685

PAGE 137

137 [ 11JMC1059 ] Shoman, M. E.; DuMond, J. F.; Isbell, T. S.; Crawford, J. H.; Brandon, A.; Honovar, J.; Vitturi, D. A.; White, C R.; Patel, R. P.; King, S. B. J. Med. Chem., 2011 54, 1059 1070 [11TL2097] Bou Moreno, R.; Luengo Arratta, S.; Motherwell, W. B. Tetrahedron Lett., 2011 52 2097 2099

PAGE 138

138 BIOGRAPHICAL SKETCH Judit Kovacs first daughter of Dr. Peter Kovacs and Zsuzsanna G yulai was born in Hungary She received her Master of Science in chemistry from Eotvos Lorand University of Science, Hungary in July 200 7 During her entire study she worked as a researcher intern with AMRI (formerly known as ComGenex) in a synthetic or ganic chemistry lab focused on combinatorial chemistry, library synthesis, and pilot study. During her fifth year, she worked as a undergraduate researcher in the Hungarian Academy of Science Chemical Research Center Institute of Biomolecular Chemistry Lab oratory of Natural Organic Compounds under the supervision of Dr. Gabor Dornyei, working on the total synthesis of epiquinamide Upon graduation, she joined the University of Florida as an adjunct assistant in chemistry under the supervision of Prof. Alan R. Katritzky. S he continued her education at the Department of Chemistry, University of Florida, from August 200 8 Her master and Ph.D. level research focused on synthesis of heterocycles supervised by Dr. Alan R. Katritzky.