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A STUDY OF ELECTRONIC INTERACTIONS
IN CERTAIN VINYL ETHERS
By
RONALD EARL THOMPSON
A DISSERTATION PRESENTED TO THE GRADUATE COUNCIL OF
THE UNIVERSITY OF FLORIDA
IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE
DEGREE OF DOCTOR OF PHILOSOPHY
UNIVERSITY OF FLORIDA
August, 1962
UNIVERSITY OF FLORIDA
3 1262 08552 2653
ACKNoULEDGIENTS
The author wishes to express his deep appreciation to
Dr. G. B. Butler whose guidance, counsel, assistance, and
encouragement during the execution of this work were of
inestimable value.
The author also wishes to express his gratitude to
Dr. W. S. Brey, Mrs. K. N. Scott, and coworkers, without whose
assistance the physical property deterr.inations could not have
been trade; to Dr. A. H. Gropp and his coworkers for their
advice and counsel in the interpretation of the infrared spectra,
to L. S. Pijanowski and H. W. Latz for the infrared spectra,
and to the members of his advisory committee and his fellow
graduate students whose advice and criticism were a constant
source of inspiration and encouragement.
Finally, the author wishes to express his great appreciation
and his sense of deep indebtedness to his wife, Roslyn, whose
forbearance, longsuffering, and understanding during months of
neglect made this work possible.
The financial support of this research by the National
Science Foundation is also gratefully acknowledged.
- ii-
TABIE OF CONTENTS
Page
ACKiO-JLEDG1 IETS ii
LIST OF TABLES iv
LIST OF FIGURES v
Chapter
I. IHTRODUCTIO; 1
Background 1
Statement and Development of the Problem 3
Delineation of Objectives and Methodology 9
Source and Purification of Frcacnts 13
II. EXPERI!INTAL 14
Preparation of the CorDounds 14
Physical IMeasurements 33
III. DISCUSSION OF RESULTS 64
Preparation of the Compounds 64
Physical Ieasurements 67
IV. SU?: ARY 82
BIBLIOGRAPHY 83
BIOGRAPHICAL SKETCH 86
-iii-
LIST OF TAPES
TADULATIOI OF
TABULATION OF
SPECTPA
TAiULATIO:I OF(
COIIPOUNDS
TABULATION OF
COMPOUNDS
COT-I;APSro:I
DIPOLE :i0:,iT DATA
MAXIMA IN ULTRA-VIOLET ABSORPTION
OTLAR PEFPACTIOHI DATA FOR VEYLOXY
E:OLAT. REFRACTION DATA FOR ETHYLOXY
YIELDS OF SYNTHETIC ETHIODS
-iV-
Table
1.
2.
3.
4.
5.
Page
35
39
62
63
65
LIST OF FIG-ULS
Figure Page
1. ULTRfA-VIOLET ABSOFPTIOI SPECTPA OF 2-VINYLOXY-
ETHOX1JIuZEiE AND 2-ETHYLOXYE'THOXYEENZEE 0O
2. ULTPA-VIOLET ABSORPTION SPECTRA OF 2-(2-VI YLOXY)-
ETHO:zI;ENZAL~iYI AND 2- (2-ETIIYLOXY)ETHOXY-
BENZALDEhIDE 41
3. ULTPA-VIOLST ABSORPTIONJ SPECTRA OF 3-(2-VhiYLOXY)-
ETHOm;Y~EiIZALDEHYIE AND 3- (2-ETHYLOXY)ETHOXY-
EElIZALDEHYTE 42
4. ULTRA-VIOLET ABSORPTION SPECTRA OF 4-(2-VINYLOXY)-
ETHOXYBENZALPElYIDE AN1D 4-(2-ETHYLOXY)ETHOXY-
BENZALnEa-YIE 43
5. ULTRA-VIOLET AESORPTIOI SPECTRA OF 2-(2-VITYLOXY)-
ETHOXYSTYRENE AND 2-(2-ETOHYrLIO)ETHOXYSTY'iEE 44
6. ULTRA-VIOLET ABSORPTION SPECTRUM OF 3-(2-VVIYLOXY)-
ETH OXYSTYVEIE 45
7. ULTRA-VIOLET AESOFPTIT; SPEC7TA OF 4-(2-VI]flLOXY)-
ETIIOXYSiTTE;iE AID 4-(2-ETHYLO: C)ETiIOX'YSTYfREIE 46
8. ULTRA-VIOLET ABSORPTION SPECTRA OF 2-(2-VINYLOXY)-
ETHO:Y- P-I!ITROSTYFXEiE AND 2-(2-ETHYLO:XY)ETHOXY-
B-NITROSTYWELfl 47
9. ULTRA-VIOLET ABSOPTIO: SPECTRaUI! OF 3-(2-ETHYLOXY)-
ETiHO:CY-B-lIITOSTYF:EITE 48
10. ULTRA-VIOLET AESORPTION SFE 'iA OF 4-(2-VI YLCY)-
ETaH- B-IJITEOSiFTZFIEi AIND 4-(2-ETILTOXY)EITHO\rY-
3P-NITTOSTYPEIE 49
CHAPTER I
INTRODUCTION
Background
In an attempt to develop a model cross-linking monomer,
Butler and Nash (1) first studied ethers containing both vinyl
and allyl groups, which were found to undergo polymerization by
a sequence of two steps. The first step, giving rise to linear
polymers from ethylene glycol vinyl allyl ether and ethylene
glycol vinyl crotyl ether, used boron trifluoride etherate as
the initiator with toluene as the solvent at -700C. These
investigators then used benzoyl peroxide as the initiator at
65oC. to cross-link the original polymer, obtaining solid
polymers, which softened at high temperatures, and which were
insoluble in the usual organic solvents. Thus the boron
trifluoride etherate initiated polymerization of the vinyl
group in the monomer; benzoyl peroxide initiated polymerization
of the unreacted allyl groups in the linear polymer.
Next they turned their attention to monomers containing
two sites of unsaturation differing very markedly in their
reactivity. Such model compounds would be the 2-vinyloxyethoxy-
B-nitrostyrenes. In as much as one of the vinyl groups was
highly electron deficient (with respect to the vinyl group in
ethylene), being directly attached to a nitro group and a
-L-
-2-
phenyl group, while the other was electron rich (with respect to
the same standard), being directly attached to an oxygen atom,
it seemed logical that compounds of this type would be ideal
for such a study.
Thus the electron deficient double bond should be polymerized
by the use of an anionic initiator, such as sodium methoxide, to
give a linear, soluble polymer, containing the unreacted vinyloxy
groups in the sidechains. Boron trifluoride etherate, which was
so successfully employed in past vinyl polymerizations of this
same group, would then be used to polynerize these residual
vinyloxy groups, producing a cross-linked, insoluble polymer.
Nash (2) reported the preparation of certain of these
compounds and found that the electron deficient beta-nitrostyrene
group was readily polymerized with sodium methoxide as initiator.
However, he also reported that the monomeric 2-vinyloxyethoxy-
B-nitrostyrcnes were unreactive towards boron trifluoride
etherate, under conditions which lead to the facile polynerization
of the Standard monomer, vinyl 2-ethylhexyl ether.
In a separate investigation, Butler (3) showed that a series
of vinyl ethers all possessed an infrared absorption peak at
8.32 nicrons (1202 cn-1) and two other carbon-carbon double bond
peaks at 6.08 and 6.18 microns (1645 and 1618 cm-1). These
compounds were readily polyncrized with boron trifluoride
etherate to give linear, soluble polymers in which the 8.32 micron
peak had disappeared and the 6.08 and 6.18 micron peaks were
considerably diminished.
-3-
Nash investigated the various isomeric 2-vinyloxyethoxy-
benzaldehydes and 2-vinyloxyethoxy-B-nitrostyrenes, and found
that all three isomers of this aldehyde possessed these infrared
absorption bands, while the 8,32 micron peak was absent in the
spectra of the 3- and 4-isomers of the reported beta-nitrostyrenes.
As can be anticipated, the three aldehydes could be polymerized
with boron trifluoride etherate. In as much as it was not
known whether the 8.32 micron peak was attributable to the
benzaldehyde moiety (as benzaldehyde also displayed a peak at
the same place) or the vinyloxy moiety, no definite conclusions
were reached on this point at that time.
Statement and Develomnent of the Problem
In as much as Nash reported that the vinyl double bond in
the vinyloxy group of the beta-nitrostyrenes was not subject to
boron trifluoride etherate polymerization, and that the infrared
spectra of these compounds did not possess the 8.32 micron peak,
the problem immediately suggested itself: are these two facts
related to a common cause? If so, what features in the structure
of these compounds are responsible for these observations? How
can these features, when and if found, be definitely shown to
be so responsible?
Taking 4-(2-vinyloxy)ethoxy-P-nitrostyrene as an example,
the classical structure of which would be I, one of the most
important contributing structures would be II. This would place
a fairly strong oxoniu ion two (saturated) carbon atoms removed
-'4-
from the oxygen atom of the vinyloxy group. Thus the tendency
of one of the unshared pairs of electrons of this oxygen aton,
to give rise, via a delocalization process, to a contributing
structure such as III would be somewhat diminished by the
induction on the part of said oxonium ion across the intervening
saturated hydrocarbon bridge.
f=CII-(
-CH2-CI2-- CH-CH2
III
To the extent to which a form such as III does not contribute
to the structure of the compound, the electron density on the
terminal carbon atom of the vinyloxy group would not be augmented
by such a delocalization process. Ibreover, this resonance
effect (+R), to use the terminology of Could (4), no longer
being considered, electrons would be attracted from the double
bond of the vinyloxy group by the inductive effect (-I) of the
oxygen atom, and the combination of these two effects would
be that the pair of electrons, constituting the pi bond of
the vinyloxy group would not be free to coordinate with the
empty orbital of the boron atom in the initiator. Since the
polymerization proceeds by this form of initiation, this would
account for the lack of reactivity of the beta-nitrostyrenes
towards boron trifluoride etherate, and hence, their lack of
Lewis acid polymerizability. Therefore, since a form such
as II does contribute strongly to the structure of the compound,
this would seem to explain the experimental data.
Gould (5) states that the pK of chloroacetic acid (chlorine
atom inducing across one methylene group) is 2.86, of beta-
chloropropionic acid (chlorine atom inducing across a two
carbon saturated hydrocarbon bridge) is 4.00, and that of
acetic acid is 4.80. Thus it is seen that, while still present,
the induction by the chlorine atom in the beta position is
quite minor as compared to that in the alpha position. Thus
it was felt that the above explanation, relying on the induction
of the oxonium ion across a two carbon saturated hydrocarbon
bridge, left something to be desired.
Another explanation was devised, wherein the contributing
forms, such as II and III are both considered to have important
and simultaneous contributions to the structure of the compound,
as in IV:
-6-
0 e
=C H-C CH-~H0
IV
Here, one of the unshared pairs of electrons of the oxygen atom
of the vinyloxy group is free to be delocalized and contribute
to the extreme form as depicted in III and IV, essentially
unhindered by the beta-oxonium ion's weak induction. However,
being highly polarized by the nearly positive charge on the
phenolic oxoniun ion, located ji atoms away, it is not free to
be donated to the empty orbital of the boron atom in the
initiator (or, at least, not as free as is one of the electron
pairs on the ethyl ether oxygen atom in the original boron
trifluoride otherate complex). To the extent to which this
polarization-favored quasi-six-nonbe red ring contributes to
the structure of the coLpound, it could as rwll explain the
experimental observations.
The construction of a model, representative of a form such
as IV, shows that such a structure is feasible. Moreover,
nanipulation of this model lead to the observation that co-planarity
between the 0-C-C system of the vinyloxy group and the 021!-C-C
phenyl-0 system of the beta-nitrostyryloxy group could be
established at the expense of having the two oxygen atoms in
the -0-CH2-CH2-O- group in the Eaughe conformation. The slight
increase in the energy of the system due to this unfavored
conformation would probably be more than overcome by the energy
-7-
lowering of a -o cloud overlap (even though across an area
between two atoms not joined by a signa bond) which could also
extend the D cloud delocalization.
Shostakovskii (6) postulated a resonance structure for
vinyl ethers, for which the rotation of the alkyl group about
the C-0 bond would be hindered, giving rise to the two rotational
isomers:
1H2C=C ,R and H2C=C
V VI
The work of Brey (7,8) and Tarrant (8) gave excellent support
for this type of isomerism. However, the formation of a ring,
as described above, would not allow the existence of both of
these isomers. The isomer, similar to the second one depicted (VI),
would correspond to IV; the other isomer, similar to the first
one depicted (V), would not allow the ring to form. Thus the
predictions would be that, based on the above explanation,
compounds of the type herein discussed, in whose infrared
absorption spectra the 8.32 micron peak is absent, or at least
significantly shifted from this value, should not be susceptible
to boron trifluoride etherate polymerization and should exhibit
only one peak of the two at (about) 6.08 and 6.18 microns.
The method of choice to investigate the above mentioned
postulation would be to obtain the infrared spectra of the
compounds to be studied. The ultra-violet spectra of those
-8-
vinyloxy compounds having a spectral shift in the 8.32 micron
peak and only one peak (the 6.18 micron peak) in the 6.08-6.18
micron region should then be compared to the ultra-violet spectra
of the corresponding ethyloxy compounds. If such an extension
of the 2j cloud deloalization does not exist, that is, if
there is no interaction between the vinyloxy ji cloud system
and the A cloud system of the beta-nitrostyryloxy portion of
the molecule, then substitution of the ethyloxy group for the
vinyloxy group should lead to the disappearance of only one
peak in the ultra-violet spectrum (and then only if the vinyloxy
group has an ultra-violet absorption maxima in the range available)
and have no change on any others present. On the other hand,
if there is an electronic interaction of the type postulated
in these vinyl ethers, the substitution of the vinyloxy group
by an ethyloxy group should produce a shift in the wavelength
and a change in the extinction coefficient of at least one of
the maxima present in the spectrum of the vinyloxy compound,
and such a shift should be toward shorter wavelength (toward
higher energy).
Another method used to investigate the polarization-favored
ring would be the determination of the dipole moment and the
molar refraction of the various cornounds. Structure IV would
be expected to have a different dipole moment than either II or
III, with III probably having the lowest value, II being
intermediate, and IV having the highest value.
If the ring is forced and a for such as IV contributes
strongly to the actual structure of the compounds, either by
-9-
the polarization-favored nech=nisa, the extension of P2 cloud
delocalization, or both, the electronic environment of the
beta-hydrogens on the vinyloxy group should be sufficiently
altered as to be detectable as a change in the chemical shift
of these hydrogen atoms in the nuclear magnetic resonance
spectra of these compounds. These determinations are being
made by Dr. W. S. Brey and coworkers, and will be reported
independently.
Delineation of Objectives and Methodolog~
The primary objectives of this investigation were the
preparation of the compounds and the determination of certain
of their physical properties. The secondary objectives were
to discover the correlation between these physical properties
and the structure of the compounds and to determine if these
correlations could be successfully employed in the explanation
of the previously reported, experimentally observed behavior
of these compounds towards polymerization.
The compounds to be prepared in this investigation were
grouped into two series: (a) ethylene glycol substituted-
phenyl vinyl ethers, and (b) ethylene glycol substituted-phenyl
ethyl ethers. Since the compounds in the second (ethyloxy)
series were somewhat similar to those in the first (vinyloxy)
series, it was decided, when applicable, to utilize the same
methods in their preparation as were employed in the preparation
of the compounds of the vinyloxy series,
-10-
The compounds to be prepared were: (a) 2-vinyloxycthoxy-
benzene, 2-, 3-, and L2.(2-vinylo:y)cthojbcnznaldehyde, 2-, 3-,
and h:-(2-vinyloxy)-ethoxystyrcne, and 2-, 3-, and h-(2-vinylory)-
ctho:y-P-nitrostyrene, and (b) 2-ethylo.yetlhoxlbcnzene, 2-, 3-,
and 4-(2-ethyloxy)ctho:ybcnzaldchyde, 2-, 3-, and 4-(2-ethyloxy)-
cthoxystyrenc, and 2-, 3-, and 4-(2-ethylo;:y)etho:cy-B-nitrostyrene.
The sinllarity of the two series is apparent.
Butler (3), in the preparation of 2-vinyloxyethoxrybcnenc,
and Nash (2), in the preparation of 2-, 3-, and 4-(2-vinyloxy)-
ethoVybenzaldehyde, used essentially the same synthetic procedure:
a basic aqueous solution of phenol or the appropriate hydroxy-
benzaldehyde, prepared in situ by dissolving the phenol in an
aqueous potassium hydroxide solution, was treated with 2-chloro-
ethyl vinyl ether. The resulting mixture was heated for some
tine (usually twenty-four hours), then cooled to room temperature,
and extracted with benzene. The benzne solution was then dried
and the bulk of the solvent removed by distillation. Fractional
distillation of the residual oil gave the desired product.
In the preliminary stages of this investigation these
methods of preparation were recheckd with excellent agreement.
However, it was felt that the relatively low yield (2-vinyloxy-
ethoxybcnzene: 21.0 per cent; 2-(2-vinyloxy)cthoxybenzaldehyde:
31.53 per cent; 3-(2-vinyloxy)ethoxybenzaldchyde: 42.46 per cent;
and 4-(2-vinyloxy)ethoxybenzaldehyde: 18.70 per cent) was at
least partially due to the hydrolysis of the 2-chloroethyl vinyl
ether by either water, present in overwhelming excess, or by an
-11-
equilibrium concentration of hydroxide ions. It was thus
decided to investigate the feasability of the isolation of the
anhydrous potassium salt of these phenols, then allowing this
potassium salt to react with 2-chloroethyl vinyl ether in some
non-hydroxylic, inert medium in which they were mutually soluble.
The solvent of choice was N,N-dinethylforramide. The results of
this phase of the investigation will be discussed under "Discussion
of Results."
Nash (2) also reported the preparation of 3. and 4-(2-vinyloxy)-
ethoxy-P-nitrostyrene. His reported method of synthesis was
rechecked and, indeed, the compounds which were thus obtained
showed excellent agrcccnt in melting point with those reported.
However, the nuclear magnetic resonance spectra of these compounds,
in failing to show the presence of any vinyloxy hydrogen atoms
in these compounds, began to cast a serious doubt on the validity
of the assignment of the reported structure of these compounds.
This doubt lead to the resubnission of these compounds for
analysis, in an even purer state on the basis of melting point
than that reported: "3-(2-vinylox)ethoxy-.-nitrostyrene,"
m.p.: 113.5-114.0oC. as compared to 112-1130C. and "4-(2-vinyloxy)-
ethoxy-0-nitrostyrene," m.p.: 123.5-124.00C. as compared to
121-1220C. The carbon, hydrogen, and nitrogen analyses of these
compounds were in good agreement with the analyses that would
be calculated for 3-(2-hydroxy)ethoxy-Bq nitrostyrene and 4-(2-hydroxy)-
ethoxy-B-nitrostyrene. Thus the final stage in the preparation of
these compounds, treatment of the basic condensation reaction
-12-
mixture of the appropriate 2-vinyloxyothoxybenzaldehyde,
nitroncthano, methanol, and aqueous potassium hydroxide solution
rith excess hydrochloric acid solution lead to tho hydrolysis
of the vinyl ether. This facile hydrolysis of vinyl others is
reported in the literature (9-13).
Thus, to the best klno~lcdgo of the author, the only compounds
included in this investigation that are nowin to have been
previously reported in the chemical literature are 2-vinyloxy-
othoxybcnzcnc and the 2-, 3-, and 4-(2-vinyloxy)cthoxybenzaldehydec,
and these compounds have been prepared by a conewhat different
method and in significantly better yields to justify their
inclusion in this series of otherwise nw, unreported corounds,
over and above the fact that they are the intermediates for
the corresponding styrenes and beta-nitrostyrenes.
Finally, in as much as these aldehyde intermediates were
synthetically available, and since benzaldehyde Ias knoim to
undergo the Wittig (14) reaction with ease, it was decided to
investigate this synthetic route to a ne series of potentially
interesting monomrs. These compounds, being 2-vinyloxyethoxy-
styrenes, would possess tWo double bonds of somewhat differing
reactivities towards polymerization, and thus my well be
ideally constituted for a polyncrization study, similar to that
conducted by Dutler and Hash (cf. Pef. 1). The synthesis of the
2-ethylo:zyethoxystyrenes was also investigated, not only due to
the fact that they would be interesting mnonomers for polymerization
studies, but also since their physical properties should be
compared to the physical properties of the vinyloxy compounds.
Since polymerization studies were outside the scope of this
investigation, no such studies were conducted.
Source and Purification of Pcarents
Phenol (U. S. P. grade, fused) was obtained from J. T. Baker
Chemical Company, Phillipsburg, Pennsylvania, and was used without
purification.
2-Hydroxybenzalcehyde (salicylaldehyde, Fisher Reagent
Chemical) was obtained from Fisher Scientific Company, Fairlawn,
New Jersey, and was used without further purification.
3-Hydroxvbenzaldehyde (practical) was obtained from L. Light
and Company, Limited, Colnbrook, England, and was used without
purification.
4-Hvdroxybenzaldehyde (practical) was obtained from Eastman
Organic Chemicals Division, Distillation Products Industries,
Rochester, New York, and was used without further purification.
Vinyl 2-chloroethyl ether was obtained from Carbide and
Carbon Chemicals Company, Union Carbide and Carbon Corporation,
New York, New York, and was used without further purification.
2-Bromoethyl ethyl ether (Reagent grade) was obtained from
Penninsular Cheresearch, Incorporated, Gainesville, Florida,
and was used without any further purification.
Butyl lithium in hexaie solution was obtained from Foote
Iinernl Company, hWest Chester, Pcnnsylvania, and was used
without purification,
lIethvltroihenylphosnhonium bronide was obtained from this
laboratory and was used without further purification.
CHAPTER II
EXPERIZEIITAL
Preparation of the Compounds
A. 2-Vinyloxyethoxybenzene.--This diether was prepared
(a) according to the method of Butler (3) and (b) by the method
described below.
1. Preparation of the potassium salt.--A solution of
47.06 g. (0.5000 mole) of phenol in 50 rl. of absolute ethanol
was added to a solution of 32.74 g. (0.5000 mole) of 85.7 per
cent potassium hydroxide in 350 nl. of absolute ethanol. The
solvent was removed by distillation; residual misture was
removed by the use of the benzene azeotrope. The lavender,
crystalline solid was washed with anhydrous ethyl ether to
remove any unreacted phenol, filtered, and dried over calcium
sulfate at reduced pressure. Due to the extremely hygroscopic
nature of this salt, it was used immediately.
2. Preparation of the diether.--The above potassium
salt was dissolved in a solution of 58.60 g. (0.5000 mole plus
10 per cent excess) of 2-ch oroothyl vinyl ether in 200 ml.
of redistilled dinethylformanide, by stirring on a steam bath.
Stirring and heating were continued for ten hours. Upon being
cooled to room temperature, the reaction mixture was diluted
-14.
-15-
with one liter of distilled water and then repeatedly extracted
with ethyl ether. The ethereal extracts were dried over anhydrous
magnesium sulfate and the bulk of the solvent removed by atmospheric
distillation. The residual oil was fractionally distilled under
vacuum to give 51.57 g. (6P.81 per cent yield) of a clear,
colorless liquid, b.p.: 103-105oC./7.5 mr. of mercury. Redistil-
lation of a 46.20 g. sample of this material gave 44.57 g.
(96.47 per cent recovery; 60.00 per cent relative over all yield)
of a clear, colorless liquid, b.p.: 102-103oC./10 mmi of mercury,
30
nD: 1.5152.
Analysis: Calculated for C10H1202, per cent: C, 73.20;
H, 7.32. Found, per cent: C, 73.10; H, 7.hl.
B. 2-(2-Vinylocy )ethoxvbenzaldehyde.--This diether was
prepared in a manner entirely analogous to that described above.
1. Preparation of the potassium salt.--The potassium
salt was prepared on a 1.0000 mole scale by the substitution of
salicylaldehyde for the phenol in the previous procedure. The
yield of yellow, crystalline solid, after drying to constant
weight, was quantitative.
2. Preparation of the diether.-This diether was
prepared on a 0.7500 mole scale from 120.0 g. of the potassium
salt, 87.9 g. of 2-chloroethyl vinyl ether, and 500 ml. of
redistilled dimethylformamide, by the procedure cited above.
Fractional distillation of this product gave 106.61 g. (73.95 per
cent yield) of a clear, colorless liquid, b.p.: 101-103oC./0.1 mm.
of mercury; n30: 1.5427.
D .
-16-
Anaysis: Calculated for C11H1203, per cent: C, 68.73;
II, 6.29. Found, per cent: C, 68.43; H, 6.25.
C. 3-(2-Vinvloxy)ethoxybenzaldehyde.--With the exception
of a slight modification in the preparation of the potassium
salt, this diether was prepared in the same manner as cited above.
1. Preparation of the potassium salt--This potassium
salt was prepared on a 0.3000 mole scale by adding 19.65 g. of
85.75 potassium hydroxide dissolved in 150 ml. of absolute
ethanol to a solution of 36.64 g. of n-hydroxybenzaldehyde in
150 ml. of absolute ethanol cooled to the vicinity of 50C.
Heat was not supplied during the vacuum distillation used to
remove the solvent. After being washed with anhydrous ethyl
ether to remove any unreacted m-hydroxybenzaldehyde, filtered,
and dried, the yield of greenish yellow, crystalline solid was
47.00 g. (97.77 per cent yield).
2. Preparation of the diether.-This diether was
prepared in the same manner as described above from 47.00 g.
(0.2934 mole) of the potassium salt, 42.63 g. (0.2934 mole
plus 36.4 per cent excess) of 2-chloroothyl vinyl ether, and
250 ml, of redistilled dinethylfornanide. Fractional distillation
of the crude product gave 46.31 g. (82.11 per cent yield) of a
clear, colorless liquid, b.p.: 106-107oc./0.50 nm. of mercury;
19
nD : 1.5470. This is the material referred to as the "liquid
notification."
Analysis: Calculated for C11H1203, per cent: C, 68.73;
I, 6.29. Found, per cent: C, 68.57; H, 6.47.
-17-
By the low temperature removal of solvent by reduced pressure
distillation of a small amount of a benzene solution of the "liquid
modification," a solid was produced. This solid was used to seed
a 15.98 g. sample of the "liquid modification," resulting in the
crystallization of a total of 13.48 e. (84.36 per cent yield) of
a white, crystalline solid, n.p.. 39.0-40.5oC. Fecrystallization
of a 10.00 g. sample of this solid from pentane gave 7.75 g.
(77.5 per cent recovery) of a white, crystalline solid, m.p.:
41.0-42.00C. This is the material referred to as the "solid
modification."
Analysis: Calculated for C11H1203, per cent: C, 68.73;
H, 6.29. Found, per cent: C, 68.89; H, 6.27.
D. 4-(2-Vinylox )ethoxybenzaldehyde.--This diether was
prepared in the same manner as 2-(2-Vinyloxy)ethoxybenzaldehyde,
described above.
1. Preparation of the potassium salt.--The potassium
salt was prepared in quantitative yield on a 0.5000 mole scale
from 61.06 g. of j-hydroxybenzaldehyde and 32.75 g. of 85.7 per
cent potassium hydroxide.
2. Preparation of the diether.--This diether was
prepared on 0.5000 mole scale from 80.11 g. of the potassium
salt, 53.28 g. of 2-chloroethyl vinyl ether, and 200 ml. of
redistilled dimethylformamide. Distillation of the crude product
gave 79.28 g. (82.49 per cent yield) of clear, light tan liquid,
b.p.: 133-1400C./lI. rn. of mercury. As the liquid crystallized
on the refractoieter platform, the index of refraction could not
-18-
be determined; however, this solid material was used to seed
the liquid. In this manner a total of 77.59 g. (97.87 per cent
recovery; 80.74 per cent over all yield) of a light tan,
crystalline solid, m.p.: 39.540.50C., was obtained. Pecrystal-
lization failed to change the melting point, but did give a white,
crystalline solid.
Analysis: Calculated for CI1H1203, per cent: C, 68.73;
H, 6.29. Found, per cent: C, 68.95; H. 6.38.
E. 2-(2-Vinvloxy )ethoxystyrene.--This styrene was prepared
by the 'ittig (14) reaction from the ethylene ylid (prepared
i ~jtu) and the previously prepared 2-(2-vinyloxy)ethoxybenzaldehyde.
1. Preparation of the methylene ylid.--Dry nitrogen gas
was passed over a vigorously stirred slurry of 89.31 g. (0.2500 mole)
of nethyltriphenylphosphonium bromide in one liter of anhydrous
ethyl ether for one hour at room temperature. Then 188 ml. of
a 14.90 per cent solution of butyl lithium in hexane was slowly
added by neans of a hypodermic syringe. After an additional
30 minutes of stirring, the yellow reaction mixture was nearly
clear.
2. Preparation of the styrene.--A solution of 48.06 g.
(0.2500 nole) of 2-(2-vinyloxy)ethoxybenzaldehyde in 250 ml. of
anhydrous ethyl ether was slowly added with constant stirring to
the above reaction mixture. The white slurry was then stirred
overnight. After the addition of one liter of distilled water
to the reaction mixture and stirring for a short time, the
two phases were separated. The aqueous phase was repeatedly
-19-
extracted with ethyl ether. These ethereal extracts were
combined with the original ethereal phase and the whole was
extracted with water, then dried over anhydrous magnesium sulfate.
Reroval of the bulk of the solvent by a reduced pressure distil-
lation gave a thick, semi-solid oil, which was repeatedly
extracted with petroleum ether. Again, the bulk of the solvent
was removed by reduced pressure distillation. The residual oil
was fractionally distilled under vacuum to give 22.26 g.
(46.80 per cent yield) of a clear, colorless liquid, b.p.:
85-890C./0.50 mm. of mercury; n9,: 1.5480-1.5485. Redistil-
lation of 20.00 g. of this material gave 15.53 g. (77.65 per cent
recovery; 36.34 per cent relative over all yield) of a clear,
colorless liquid, b.p.: 90-91C./0.70 mn. of mercury; n7.5: 1.5441.
Analysis: Calculated for C12H1402, per cent: C, 75.76;
H, 7.42. Found, per cent: C, 75.68; H, 7.20.
F. 3- (2-Vinylox)ethoxystyrene .--This styrene was prepared
in exactly the same manner as described above.
1. Preparation of the methylene ylid.--The methylene
ylid was prepared in exactly the same manner as described above,
but on a 0.1000 mole scale, from 35,73 g. of nethyltriphenyl-
phosphonium bromide, 90 ml. of a 15.04 per cent solution of
butyl lithium in hexane, and 350 nl. of anhydrous ethyl ether.
2. Preparation of the styrene.--This styrene was
prepared as described above, but on a 0.1000 mole scale.
Distillation of the crude production gave 8.46 g. (44.48 per cent
yield) of a clear, colorless liquid, 89-114C./0.08 mm. of mercury;
-20-
30
nD : 1.5325-1.5410. Combination of this material and that
produced by a subsequent synthesis to give a starting charge
of 17.00 g. and redistillation gave a total of 12.10 g. (71.18 per
cent recovery; 31.80 per cent relative over all yield) of a
clear, colorless liquid, b.p.: 79-84oC./0.06 nv. of mercury;
n3O: 1.5435.
Analysis: Calculated for C12i1402, per cent: C, 75.76;
H, 7.42. Found, per cent: C, 75.85; H. 7.47.
G. 4-(2-Viryvloyy)ethoxystyrene.--This styrene was prepared
in an analogous manner to that described above, but was purified
differently.
1. Preparation of the methylene ylid.--The ethylene
ylid was prepared exactly as described above on a 0.2000 mole
scale from 71.45 g. of methyltriphenylphosphoniun bromide,
150 nl. of a 15.04 per cent solution of butyl lithium in hexane,
and 750 ml. of anhydrous ethyl ether.
2. Preparation of the styrene.--The same procedure,
as described above, was followed up to the point of the reduced
pressure distillation of the petroleum ether solvent. At this
point, instead of a residual oil, 28.00 g. (72.82 per cent yield)
of a waxy, white solid was obtained. This material melted
(m.p.: 54-560C.) to give a cloudy melt, suggesting the presence
of triphenylphosphine oxide as an impurity, Chronatographic
purification over an activated alumina column, followed by
recrystallization of the product, gave a total of 19.14 g.
(68.35 per cent recovery; 49.77 per cent over all yield) of
lustrous, white flakes, m.p.: 59.5-60.5oC.
Analysis: Calculated for C12H1402, per cent: C, 75.76;
H, 7.42. Found, per cent: C. 75.59: H. 7.19.
H. 2-(2-Vinyvlo~e-)ethoxy- -nitrostyrene.--Fundanentally these
compounds were made according to the method of Thiele (15), with
slight modifications, as described below. A solution of 48.05 g.
(0.2500 mole) of 2-(2-vinyloxy)ethoxybenzaldehyde, 15.26 g.
(0.2500 mole) of redistilled nitromethane, and 250 ml. of
ethanol was cooled in an ice bath to the vicinity of 50C.
with constant stirring. A solution of 16.37 g. (0.2500 mole)
of 85.7 per cent potassium hydroxide in 50 rl. of distilled
water and 100 ml. of methanol was added dropwise, at such a
rate that the temperature of the reaction mixture did not rise
above 50C. The clear, greenish yellow solution was then poured
over 250 g. of ice in a separatory funnel and the resulting
white mixture was slowly poured into a vigorously stirred
mixture of 22.5 ml. of concentrated hydrochloric acid solution,
250 g. of ice, and 250 nl. of cold, distilled water. The yellow
precipitate was filtered under suction, immediately washed with
two liters of cold, distilled water, and then with one liter
of distilled water at room temperature, and then sucked air dry.
A total of 53.23 g. (90.51 per cent yield) of yellow powder,
m.p.: 56-580C., was obtained.
Eccrystallization of a 25.00 g. sample of this material from
ethanol gave a total of 15.00 g. (60.00 per cent recovery;
54.31 per cent relative over all yield) of a fine, yellow,
-22-
crystalline solid, m.p.: 62.0-62.5oC. Subsequent recrystallizations
failed to change the nelting point.
Analysis: Calculated for C12I13i04, per cent: C, 61.27; 1
N, 5.95. Found, per cent: C. 61.44; H, 5.71. N. 5.91
I. 3- (2-Vinyloxy)ethox-B-nitrostvrene .--Despite repeated
attempts to synthesize this compound, either using e-."t'l" the
procedure developed for the successful synthesis of 2-(2-vinyloxy)-
ethoxy-~-nitrostyrene, or modifications in addition rate,
addition time, or addition order, no successful synthesis for
this compound has as yet been developed.
J. l- (2-Vinyloxy)ethoxy-8-nitrostrene .--The procedure
developed for the above synthesis was successful for the synthesis
of this compound from 19.23 g. (0.1000 mole) of 4-2-vinyloxy)-
ethoxybcnzaldehyde, 6.11 g. (0.1000 mole) of redistilled nitro-
methane, and 125 ml. of ethanol, with a basic solution of
6.55 g. (0.1000 mole) of 85.7 per cent potassium hydroxide
dissolved in 20 ml. of water and 40 ml. of methanol, and an
acidic solution of 9.0 ml. of concentrated hydrochloric acid
solution, 100 g. of ice, and 100 ml. of cold distilled water.
The product obtained was a yellow powder, m.p.: 107-1080C.,
with a yield of 12.70 g. (53.97 per cent). Recrystallization
fron absolute ethanol gave 9.50 g. (74.85 per cent recovery;
40.40 per cent over all yield) of bright yellow crystals,
m.p.: 108.0-108.50C.
Anarysis: Calculated for C121 3104, per cent: C, 61.27;
H, 5.57; H, 5.95. Found, per cent: C, 61.21; H, 5.51; !I, 5.95.
-23-
K. 2-Ethyloxyethoxybenzene.--This diether was prepared in
the same manner as 2-vinyloxyethoxybenzene.
1. Preparation of the potassium salt.--A solution of
13.53 g. (0.2500 mole) of phenol in 50 ml. of absolute ethanol
was added to a solution of 16.37 g. (0.2500 mole) of 85.7 per
cent potassium hydroxide in 100 ml. of absolute ethanol. The
solvent was removed by distillation at reduced pressure; residual
moisture was removed by the use of the benzene azeotrope. The
lavender, crystalline solid was washed with ethyl ether, then
dried over calcium sulfate under reduced pressure. The yield
of dry salt was 30.45 g. (99.67 per cent).
2. Preparation of the diether.--The above potassium
salt was dissolved in a solution of 42.10 g. (0.2500 mole plus
10 per cent excess) of 2-bromoethyl ethyl ether in 150 ml. of
redistilled direthylfornamide by stirring on a steam bath.
Stirring and heating were continued for ten hours. Upon being
cooled to room temperature, the reaction mixture was diluted
with one liter of distilled water and repeatedly extracted with
ethyl ether. The ethereal extracts were dried over anhydrous
magnesium sulfate and the bulk of the solvent removed by
atmospheric distillation. The residual oil was fractionally
distilled under vacuum to give 18.81 g. (45.26 per cent yield)
of a clear, colorless liquid, b.p.: 101-102oC./7.0 mm. of mercury;
n3 1.4958-1.4967. Redistillation gave 12.45 g. (66.19 per
cent recovery; 29.96 per cent over all yield) of a clear, colorless
liquid, b.p.: 101-1020C./7.5 nm. of mercury; n0: 1.4960; d30:
0.9971 g./ml.
-24-
Analysis: Calculated for C10H1402, per cent: C, 72.26;
H, 8.49. Found, ner cent: C, 72.07; H, 8.42.
L. 2- (2-Ethyloxy )ethoxyben.zaldeh.yd .--This diether was
prepared in a manner analogous to that used in the preparation
of 2-(2-vinyloxy)ethoxybenzaldchyde.
1. Preparation of the potassium salt.-A solution of
122.12 g. (1.0000 mole) of salicylaldchyde in 50 ml. of 95 per
cent ethanol was slowly added to a solution of 65.48 g.
(1.0000 mole) of 85.7 per cent potassium hydroxide in 350 ml.
of 95 per cent ethanol, with stirring in an ice bath. The
yellow potassium salt was removed by filtration, washed with
pentane, and then ethyl ether. A large amount of ethyl ether
was added to the filtrate and the resulting mixture was filtered
and washed with ethyl ether. The crops of potassium salt were
combined and dried at reduced pressure. The yield (160.2 g.)
was quantitative.
2. Preparation of the diether.-A solution of 40.05 g.
(0.2500 mole) of the potassium salt in 42.09 g. (0.2500 mole
plus 10 per cent excess) of 2-bromethyl ethyl ether and 150 nl.
of redistilled diethylformanide was heated on the steam bath
for ten hours with constant stirring. Upon being cooled to
room terperaturc, the reaction mixture was diluted with 600 nl.
of distilled water, then repeatedly extracted with ethyl ether.
The ethereal extracts were dried over anhydrous magnesium sulfate
and were then reduced to a small volume of residual oil by the
atmospheric distillation of the solvent. Fractional distillation
-25-
of the residual oil under vacuum gave 40.26 g. (82.91 per cent
yield) of a clear, light yellow liquid, b.p.: 94-980C/0.08 am.
of mercury; n : 1.5225. Combination of this material and that
from a subsequent run and redistillation gave a total of 69.50 g.
of a clear, colorless liquid (from a starting charge of 104.80 g.),
a recovery of 66.32 per cent and a relative over all yield of
54.99 per cent; b.p.: l15-l160C./I.0 mr. of mercury; n0: 1.5250;
d3.0 1.0785 g./ml.
Analysis: Calculated for CllH1403, per cent: C, 68.02;
H, 7.27. Found, per cent: C, 67.93; H, 7.23.
M. 3-(2-Ethyloxy)ethoxybenzaldehyde.--This diether was
prepared in a manner analogous to that used for 3-(2-vinyloxy)-
ethoxybenzaldehyde.
1. Preparation of the potassium salt.--A solution of
16.37 g. (0.2500 mole) of 85.7 per cent potassium hydroxide in
100 ml. of 95 per cent ethanol was added to a solution of
30.53 g. (0.2500 mole) of j-hydroxybenzaldehyde in 100 ml. of
95 per cent ethanol and the resulting solution was evaporated
to dryness under vacuum without the application of heat. The
light brown, crystalline solid was not isolated, but was
immediately used for the next step.
2. Preparation of the diether.--The potassium salt
was dissolved in a solution of 38.26 g. (0.2500 mole) of 2-bromoethyl
ethyl ether in 200 ml. of redistilled dimethylformanide. This
solution was heated on the steam bath with constant stirring for
five hours. The reaction mixture was cooled to room temperature
-26-
and diluted with one liter of distilled water. This mixture
was repeatedly extracted with ethyl ether. The ethereal extracts
wore dried over anhydrous magnesium sulfate, then were reduced
in volume to a residual oil by the atmospheric distillation of
the solvent. Fractional distillation of this oil under vacuum
gave 31.42 g. (64.72 per cent yield) of a clear, colorless
liquid, b.p.: 114-118oC./0.80 am. of mercury; n30: 1.5182-1.5228.
Redistillation of 50.00 g. of a combination of this material
and that from a subsequent run gave 48.06 g. (96.12 per cent
recovery; 62.21 per cent relative over all yield) of a clear,
colorless liquid, b.p.: 104-105.C./0.5 m. of mercury; 30: 1.5234;
d30: 1.0799 g./ml.
"Analsir: Calculated for C11H1403, per cent: C, 68.02;
H, 7.27. Found, per cent: C, 67.86; H, 7.48.
N. 4- (2-Ethyloxy)ethoxybenzaleydhde.--This diether was
also prepared in a manner similar to that used for the corresponding
vinyloxy compound, but was purified by distillation.
1. Preparation of the potassium salt.-A solution of
65.48 g. (1.000 mole) of 85.7 per cent potassium hydroxide in
250 ml. of 95 per cent ethanol was added to a solution of
122.12 g. (1.000 mole) of n-hydroxybenzaldehyde in 250 ml. of
95 per cent ethanol. The solvent was removed on the steam bath
under reduced pressure. The lavender solid was ground to a
powder, washed with anhydrous ethyl ether, filtered, and dried.
The yield was quantitative.
2. Preparation of the diether.--The potassium salt was
dissolved in a solution of 153.03 g. (1.000 mole) of 2-bromoethyl
-27-
ethyl ether in 500 ml. of redistilled dimethylformamide. The
solution was heated on the steam bath with constant stirring
for ten hours. After cooling to room temperature, the reaction
mixture was diluted with 3 liters of distilled water, and then
repeatedly extracted with ethyl ether. The ethereal extracts
were dried over anhydrous nagnesiun sulfate and then reduced
in volume to a residual oil by the atmospheric distillation of
the solvent. Fractional distillation of this residual oil under
vacuum gave 153.17 g. (78.86 per cent yield) of a clear, pink
liquid, b.p.: 128-1300C./1.4 .am. of mercury; 30: 1.5389-1.5409.
Redistillation of a 152.00 g. sample of this material gave 128.38 g.
(82.48 per cent recovery; 64.56 per cent relative over all yield)
of a clear, colorless liquid, b.p.: 127-128oC./1.2 mm. of mercury;
n0: 1.5401; d30: 1.0866 g./ml.
Analysis: Calculated for C1H1403, per cent: C, 68.02;
H, 7.27. Found, per cent: C, 67.86; H, 7.27.
0. 2-(2-Ethyloyy)ethoxystyrene.--This styrene was prepared
in the same manner as the corresponding vinyloxy compound.
1. Preparation of the methylene ylid.--Dry nitrogen
gas was passed over a vigorously stirred slurry of 71.45 g.
(0.2000 mole) of methyltriphenylphosphonium bromide in 500 ml.
of anhydrous ethyl ether for 30 minutes. With the system still
under nitrogen sweep, 180 ml. (0.2000 mole plus 44 per cent excess)
of a solution of 14.95 per cent butyl lithium in hexane was slowly
added by means of a hypodermic syringe. After an additional
30 minutes of stirring under nitrogen sweep, the solution was
nearly clear.
-28-
2. Preparation of the styrone.--A solution of 38.48 g.
(0.1981 mole) of 2-(2-ethyloxy)ethoxybenzaldehyde in 100 ml.
of anhydrous ethyl ether was added dropwise. After an additional
30 minutes of stirring, 250 ml. of water was added and stirring
was continued until two definite phases were detected and no
more gas was evolved. The ethereal layer was separated and the
aqueous layer was extracted with ethyl ether. The ethereal
solutions were combined, back-extracted with water, and then
dried over anhydrous magnesium sulfate. Evaporation of the
solvent by reduced pressure distillation gave a residual oil,
which was fractionally distilled under vacuum to give 12.45 g.
(32.69 per cent yield) of a clear, colorless liquid, b.p.:
69-72oC./0.03 in. of mercury; n30: 1.5245.
Salys Calculated for C12H1602, per cent: C, 74.97;
H, 8.39. Found, per cent: C, 74.89; H, 8.56.
P. (2-Ethyloxy)ethoxystyrene.--This styrene was prepared
in the sam manner as the corresponding vinyloxy corpourd.
1. Preparation of the methylene ylid.--Dry nitrogen
gas was passed over a vigorously stirred slurry of 26.87 g.
(75.2 millinoles) of methyltriphenylphosphonium bromide in
300 al. of anhydrous ethyl ether for 15 minutes. With the
system still under nitrogen sweep, 50 ml. (80.0 millimoles;
75.2 millimoles plus 6.38 per cent excess) of a 14.95 per cent
solution of butyl lithium in hexane was slowly added by means
of a hypodermic syringe. After an additional 15 minutes of
stirring under nitrogen sweep, the reaction mixture was nearly
clear.
-29-
2. Preparation of the styrene.--A solution of 14.60 g.
(75.2 millimoles) of 3-(2-ethyloxy)ethoxybenzaldehyde in 100 ml.
of anhydrous ethyl ether was then added dropwise to the above
reaction mixture. After two hours of additional stirring, 200 ml.
of distilled water was added and stirring was continued until
two definite phases were detected and no more gas was evolved.
The aqueous phase was separated from the ethereal phase and was
repeatedly extracted with ethyl ether. These ethereal extracts
were combined with the original ethereal phase. This ethereal
solution was extracted with water, dried over anhydrous magnesium
sulfate, and reduced in volume to a residual oil by the reduced
pressure distillation of the solvent. Fractional distillaticn
of this residual oil under vacuum gave 9.65 g. (66.74 per cent
yield) of a clear, colorless liquid, b.p.: 90-92OC./0.10 lm. of
mercury; rn0: 1.5240.
The infrared absorption spectrum and the nuclear magnetic
resonance spectrum of this material indicated the presence of
the unreacted starting aldehyde. Up to the time of this writing,
no satisfactory method for the separation of the styrene from
the aldehyde, for the destruction of the aldehyde, or for the
complete conversion of the unreacted aldehyde into product
styrene has been developed. This problem is under active
investigation at the present time.
Analysis: Calculated for C12H1602, per cent: C, 74.97;
H, 8.29. Found, per cent: C, ; H,
-30-
Q. Il(2-Ethyloxv)etho styrene.--This styrene as prepared
in a manner similar to that used for the synthesis of the
vinyloxy compound.
1. Preparation of the rethylene ylid.--This non-isolated
intermediate was prepared on a 0.1000 mole scale in the manner
previously used front 35.72 g. of methyltriphenylphosphoniun
bromide, 400 ml. of anhydrous ethyl ether, and 90 ml. of a
14.95 per cent solution of butyl lithium in hexane.
2. Preparation of the styrene.--The procedure, used
for the successful synthesis of 2-(2-ethylox,) ethoxystyrene,
was followed, using the above methylene ylid solution and a
solution of 19.42 g. (0.1000 mole) of 4-(2-ethyloxy)ethoxy-
benzaldehyde in 100 ml. of anhydrous ethyl ether, followed
by three liters of distilled water. Fractional distillation
of the residual oil under vac-uu gave 8.19 g. (42.59 per cent
yield) of a clear, colorless liquid, b.p.: 103-1050C/l.l mn.
of mercury; n 0 1.5315. An infrared absorption spectrum and
a nuclear magnetic resonance spectrum of this material showed
that there was no detectable amount of contamination with
unreacted aldehyde.
Analysis: Calculated for C12H1602, per cent: C, 74.97;
H, 8.39. Found, per cent: C. 74.92; H, 8.49.
R. 2- (2-Ethyloxy)ethoxy-t-nitrostyrene .--A solution of
19.42 g. (0.1000 mole) of 2-(2-ethyloxy)ethoxybenzaldehyde,
6.10 g. (0.1000 mole) of redistilled nitromethane, and 100 ml.
of nethanol was cooled in an ice bath with constant stirring
-31-
to the vicinity of 50C. Then 100 ml. of a 1.00 N aqueous
solution of potassium hydroxide was added at such a rate that
the temperature of the reaction mixture did not exceed 10OC.
Poured over 100 g. of ice in a separatory funnel, this cloudy
mixture was slowly added to a constantly stirred mixture of 100 ml.
of a 1.00 N aqueous hydrochloric acid solution and 200 g. of ice.
Filtration of the resulting thick, yellow suspension, followed by
washing with cold distilled water, and suction drying, gave
16.32 g. (68.77 per cent yield) of a yellow powder, m.p.: 35-35OC.
Recrystallization from methanol gave 11.22 g. (68.75 per cent
recovery; 47.28 per cent over all yield) of yellow crystals,
m.p.: 37.0-38.OOC. A final recrystallization of this material
gave a total of 11.00 g, (98.04 per cent recovery; 46.35 per cent
over all yield) of yellow crystals, m.p.: 38.0-38.5C.
Analysis: Calculated for C12H15N0, per cent: C, 60.75;
H, 6.37: N. 5.90. Found, per cent: C, 60.63; H, 6.50; N, 5.92.
S. 3-(2-Ethyloxy)ethoxy---nitrostyrene.-After cooling a
solution of 19.42 g. (0.1000 mole) of 3-(2-ethyloxy)ethoxybenzaldehyde,
6.10 g. (0.1000 mole) of nitromethane, and 100 ml. of methanol to
the vicinity of 50C. in ice with constant stirring, 100 ml. of a
1.00 N aqueous solution of potassium hydroxide was added at such
a rate that the temperature of the reaction mixture did not
exceed 100C. The yellow solution was poured over 100 g. of ice
in a separatory funnel, then added drop by drop to a mixture of
100 ml. of a 1.00 N aqueous hydrochloric acid solution and 100 g.
of ice, vigorous manual stirring being employed throughout the
-32-
addition. The thick, yellow slurry was then filtered, washed
with cold water, and dried by suction. After drying over
anhydrous calcium sulfate under vacuum overnight, the yield of
dry, yellow powder was 19.00 g. (83.59 per cent yield), n.p.:
36-390C. Recrystallization from rnethanol gave a total of
13.35 g. (70.26 per cent recovery; 56.26 per cent over all
yield) of yellow flakes, m.p.: 43.0-C4.OOC. A final recrystal-
lization from a 50-50 mixture of ethyl ether and pentane gave
12.00 g. (96.78 per cent recovery; 50.57 per cent over all yield)
of yellow, crystalline material, m.p.: 44.5-45.00C.
Analyi? : Calculated for C12H5N 04, per cent: C, 60.75;
H, 6.37; N, 5.90. Found, per cent: C, 60.64: H, 6.24; N, 5.91.
T. 4- (2-Fthyloxv)ethoxv-B-nitrost.rene. -After a solution
of 19.42 g. (0.1000 mole) of 4-(2-ethyloxy)ethoxybenzaldehyde,
6.10 g. (0.1000 mole) of nitromethane, and 100 ml. of methanol
was cooled in an ice bath with constant stirring to the vicinity
of 50C., 100 ml. of a 1.00 N aqueous solution of potassium
hydroxide was added at such a rate that the temperature of the
reaction .ixture did not exceed 100C. The reaction mixture was
then poured over 100 g. of ice in a separatory funnel, then
added with vigorous manual stirring to a mixture of 100 ml. of
a 1.00 aqueous hydrochloric acid solution and 100 g. of ice.
The resulting yellow slurry was filtered, washed with cold water,
and sucked air dry. A total of 16.35 g. (68.82 per cent yield)
of yellow powder, m.p.: 55-650C., was thus obtained. Recrystal-
lization of this material from methanol gave a total of 9.71 g.
-33-
(59.46 per cent recovery; 41.21 per cent over all yield) of
fine, yellow needles, m.p.: 74.0-74.5Oc.
Analysis: Calculated for C12H15N04, per cent: C, 60.75;
H, 6.37; N, 5.90. Found, per cent: C, 60.82; H, 6.45; N, 5.89.
PhFysic-. rncsure-ents
A. Dinole fob-ent Measurerent.--The method of Popov and
Holm (16) was used exclusively. Briefly, this consisted of
making up solutions of varying concentrations on a weight/weight
basis for each of the desired compounds in benzene (or dioxane)
and determining the dielectric constant, the specific volume,
and the square of the index of refraction for each of the
solutions. These values were then plotted against the weight
fraction of solute, W2, for each solution. The best straight
line was then drawn through these experimental points and
extrapolated to infinite dilution (W2 = 0). Determination of
the intercept and the slope of the line for each of the three
above-mentioned determinations gave, respectively, the values
el and a, 1/ and 8, [(n0)12 and y. These quantities were
used to determine the quantities P2, and PM, the polarization
of the solute at infinite dilution and the molar refraction,
respectively, by the relations:
=( +) + (21 + LT)(e2-
2 32) 2) + (111 + 0)(n)1 1)
. .M 1 ) ;? -d + 2 ( nq ) ) 2 )
These quantities, in turn, were used in the determination of ,
the dipole moment, by the expression:
,4= (0.2230)(P2 )1/2
A rigorously purified sample of anisole was used to determine
the accuracy of the method. The experi-ntal data are tabulated
in Table 1.
1. Purification of the solvents:
a. Benzen.--The benzene used was Phillips "Pure
Grade, 99 mole per cent minimum." This was dried and fractionally
distilled over sodium ribbon. The distillate boiling at ambient
pressure between 80-81oC. was collected, and cooled three-fourths
of the sample was frozen. The crystals were isolated by decan-
tation, and were allowed to melt. The nelt was stored over
sodium ribbon and redistilled immediately before use.
b. 1,4-Dioxane.--The dioxane used was ~ atheson,
Coleman, and Bell's "Spectroquality Reagent" grade. This was
dried over calcium hydride, filtered, and distilled at ambient
pressure over anhydrous calcium sulfate. The distillate boiling
between 100.5-101.50C. was collected, and cooled until three-
fourths of the sample was frozen. Front this point on, it
received the same treatment as described above.
2. Apparatus used:
a. Capacitance cell.--The capacitance cell was
supplied by Balsbaugh Laboratories and was a modified type 2TN25,
having a determined caoacitance at 30.0aC. of 24.53 micromicrofarads,
at a frequency of 10 kc.
-34-
-35-
C' '.0 N 0 O H H C
S\ Uo oo\ ON c
H 0 0 r.0 0
1-4 4. * * *
S o o o o a O
o uo -- o H
H 4 N H H H mc
"3 C' 0 N \ C C) O 0
., , * * * *
nH --' l m C r-. a
N N oN N N N N N 0
E 0O p
Hl rl \ rN r H 0
S08 0 0 0 c o "0
SC C CO C C 0
|
0 0N C 0 H 0 c
ci O O O O O O
4 l C N 0 N H N
E- x\ ll l o o l
U O O 0 0C
U' 0C 0 \ 0 0o 0
So cN No N N N l Ni A
4 C4 4 4 4 4 4 4 .
0 o
0 1 I
A C^ c1 -4^ -4! A
-36-
V, CO mN 41 C8
Q U CO N 0
S C' C \ \ C-
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S O 0 r C o-
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H. H NO 4 I H O
c co o o N o 0
H N C> NN N 0 C0
O 0 0 0 Hr 0 H
O O'O O O O
V O CO CO Oi O i O
0 0 0 0 0 0 0 0
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C4 4 C4 C4 C C4 C4
o o o o o o- o ,0
t o o o oO o1
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0 co 0 o0
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9 Cl P\ < C CM N C- N
\ N H N tN 0
0 N W ii Wi r-I N
0 H r-H H -I H 4 0
S0 o0 o o C o\
0 C 0 S
O cH H
C0 C0 0 C0 C0 C0 0 0
0 9 0 0 0 0 N 4
S N H H N N 'V.
00 0 "t
a' i C- C, o
0 2 p ri o" A H
N cN N N- 0 N
-37-
S\30 Lt
cO rc
$ o
No o
o o C.
*
Co
o O C-
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0 0
g
C> 0
\0
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00
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$ ~5 o
b. Capacitance bridge.-The capacitance bridge
was GCneral Radio Company Type 716-C, operated by the substitutional
method, at a frequency (fo) of 10 kc. and a factor (M) of 1.
c. Oscillator.-The oscillator was General Radio
Company Type 1302-A, operated at a frequency of 10 kc.
d. Substitutional capacitor.--This was General Radio
Company Type 722-N, using 400 4D icromicrofarads as the zero base.
B. Ultra-violet Absorotion Snectra.-The ultra-violet
absorption spectrum of each compound was obtained for various
concentrations of the compound in abo Tlnt ethanol solution.
A Bausch and Lomb Spectronic 505 double-beam recording spectro-
photometer .as used with a matched pair of 1.000 ca. quartz
cells, using a latched set of 9.90 im. quartz spacers. The
absorbance values for the various solutions were corrected for
solvent absorbance, by recording solvent against solvent on the
same paper used for the spectra of the compound used as solute,
and subtracting these values from the observed absorbance values.
These corrected absorbance values were then plotted against the
concentration of the solutions, thus giving a check of the
applicability of Beer's law. Only values which showed good or
better applicability of Beer's law were used in the determination
of the extinction coefficient. The results of these studies
are briefly sunnarized in Table 2, and are given in detail in
Figures 1-10.
C. Infrared Absorption Spectra.--The infrared absorption
spectrum of each compound was obtained using (a) plates or thin
-39-
TABLE 2
TABULATION OF IAXI A DI ULTRA-VIOLET ABSORPTION SPECTRA
Alkyloxy Substituent
Cozoound
Vinylo:y
y(ne)
2- Alkyloxvethoxy-
benzene
2-(2-Alkyloxy)ethoxy-
benzaldehyde
3- (2-Alkyloxv)ethoxy-
benzaldehyde
- (2-Alkyloy )ethoxy-
benzaldehyde
2- (2-Alkyloxy)ethoxy-
styrene
3- (2-Allvloxy)cthoxy-
styrene
4- (2-Alkyloxy)ethoxy-
styrene
2-(2-AIkyloxy)ethoxy-
--nitrostyrene
3- (2-Alkyvloxy)cthoxy-
0-nitrostyrene
4-(2-Alkyloyy)ethoxy-
B-nitrostyrene
218.5
265.0
270.0
276.5
213.0
252.0
317.0
217.0
251.0
310.0
205.5
218.0
274.5
207.0
247.5
299.0
214.0
249.0
294.0
208.0
261.5
280.0
288.0
199.0
240.0
300.0
346.0
0 0
. .
195.5
.236.0
346.0
2Z,-,
loglo
3.92
3.11
3.24
3.17
4.27
3.95
3.60
4.36
3.92
3.44
4.09
4.14
4.26
4.44
4.10
3.59
4.47
4.06
3.36
4.24
4.18
3.89
3.80
4.50
3.92
4.03
4.03
. .
. .
4.53
4.02
4.32
Ethoxy
(-,a An )
195.0
220.5
271.0
277.5
214.0
251.0
318.0
218.5
251.5
310.0
197.0
219.0
275.0
210.0
246.0
300.0
. @
205.0
258.5
290.0
303.0
201.0
242.5
302.5
350.0
202.5
222.0
248.0
307.0
197.0
239.0
350.0
loglOC
4.53
3.94
3.26
3.18
4.36
4.06
3.71
4.41
4.00
3.50
4.24
4.15
4.30
4.40
4.12
3.65
4.34
4.37
3.49
3.23
4.45
3.97
4.08
4.03
4.39
3.94
3.88
4.19
4.37
4.01
4.32
-40-
*1
O
H1
.......
I
o o1 0 0 0 u1 C0
NC 0 O CJ C (N4 0
4 4t- 4d- C^ (NI fN (4 C
3010011
- 41-
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C 0o c- Vn C-
-4 4 CA (S c, c4
O3lori
0
CO
0
cv
C)
0,M
14
v" o C ,
a r\
CM o c
*
-42-
0
,,
A
I
CA
^- ^-
1f |
en
30T010
-43-
o U 0 0 N o0
o C- c- 0 C CA
II
H'-
.r1
c'
^H o
-44-
0\ O g
4 4 cv- l
cl C l
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('4 N N
CC (
CJ du d
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o 4 o v o cu- o
'c C^ 0c (C ) C\J 00
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cuc
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(V
C,
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4^-^
0
0
301301
-.7-
CO
00
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E
co
co
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Fn
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o /
o
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o III
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S\.I
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Cr
00e
01
Hc\
-50-
cells with the neat liquid, in the case of liquid compounds,
and (b) carbon tetrachloride solution, Nujol or a similar oil
mull, potassium bromide pellet, or liquid melt, as appropriate,
for solid compounds. Both sodiun chloride and calcium fluoride
prisms were used. Using all of these variables, the spectrum
of each cornound reported represented the best of the obtained
spectra. A Perkin-Elmer Corporation IMdel 21 double-beam
recording spectrophotometer was used for all spectra. In the
following description of the spectra, the following order is
used: frequency, in wavenumbers (em-1), relative intensity of
the peak (strong, s.; medium, m.; and weak, w.), its shape
(sharp, s.; moderate, m.; and broad, b.), and the assignment
of the peak.
1. 2-Vinyloxyethoxybenzene.--3125 w., m., C-H stretch
of the alpha hydrogen of vinyloxy group; 3067, m., b., asymmetric
C-H stretch of beta hydrogens of vinyloxy group; 3049, m., s.,
symmetric C-H stretch of beta hydrogens of vinyloxy group;
2924, s., s., assymetric C-H stretch in ethylene group; 2882, s.,
s., symmetric C-H stretch in ethylene group; 1639, 1621. s., s.,
C-C stretch in vinyloxy group; 1600, 1587, 1495, all s., s.,
C-C stretch in phenyl group; 1435, s, s., C-H bend in ethylene
group; 1366, m., s., C-C stretch in ethylene group; 1321, s., s.,
asymmetric C-C stretch in vinyloxy group; 1302, 1294, m., s.,
symnetric C-C stretch in vinyloxy group; 1245, s., s., phenyl
C-0 stretch in phenyl ether; 1199, s., s., vinyl C-0 stretch
in vinyloxy group; 1175, m., s., aliphatic C-0 stretch in ethoxy
group.
-51-
2. 2-(2-Vinyloxy)ethoxybenzaldehyde.--3067, w., m.,
C-H stretch of beta hydrogens in vinyloxy group; 2924, w., s.,
asymmetric C-H stretch in ethylene group; 2874, w., s., symmetric
C-H stretch in ethylene group; 1689, s., s., C-0 stretch in
aldehyde group; 1639, 1621, m., s., C-C stretch in vinyloxy
group; 1600, 1484, s., s., C-C stretch in phenyl group; 1453,
m., s., C-H bend in ethylene group; 1397, m., s., C-C stretch
in phenyl-aldehyde group; 1366, s., s., C-C stretch in ethylene
group; 1322, s., s., asymmetric C-C stretch in vinyloxy group;
1289, s., s., symmetric C-C stretch in vinyloxy group; 1244,
s., s., phenyl C-0 stretch in phenyl ether; 1198, s., s.,
vinyl C-0 stretch in vinyloxy group; 1155, m., s., aliphatic
C-0 stretch in ethoxy group.
3. 3-(2-Vinyloxy)ethoxybenzaldehyde.--3067, w., s.,
asymmetric C-H stretch of beta hydrogens in vinyloxy group;
2941, m., s., symmetric C-H stretch of beta hydrogen in vinyloxy
group; 2882, w., s., asymmetric C-H stretch in ethylene group;
2849, w., s., symmetric C-H stretch in ethylene group; 2825,
2740, w., s., C-H stretch in aldehyde group; 1695, s., s.,
C-0 stretch in aldehyde group; 1639, 1621, m., m., C-C stretch
in vinyloxy group; 1597, 1585, 1484, s., s., C-C stretch in
phenyl group; 1449 s., s., C-H bend in ethylene group; 1389,
m., s., C-C stretch in phenyl-aldehyde group; 1362, w., s.,
C-C stretch in ethylene group; 1323, s., s., asymmetric C-C
stretch in vinyloxy group; 1282, s., s.. symmetric C-C stretch
in vinyloxy group; 1264, s., m., phenyl C-0 stretch in phenyl
- 2-
ether; 1199, s., s., vinyl C-0 stretch in vinyloxy group;
1164, m., s., aliphatic C-0 stretch in ethoxy group.
4. 4-(2-Vinyloxy)ethoxybenzaldehyde.-- 3125, w., s.,
C-H stretch of alpha hydrogen in vinyloxy group; 3077, w., s.,
asymmetric C-H stretch of beta hydrogens in vinyloxy group;
2941, w., m., synetric C-H stretch of beta hydrogens in vinyloxy
group; 2882, w., m., asymetric C-H stretch in ethylene group;
2874, w., s., symxetric C-H stretch in ethylene group; 2817,
2732, w., s., C-H stretch in aldehyde group; 1704, s., s.,
C-0 stretch in aldehyde group; 1639, 1618, s., s., C-C stretch
in vinyloxy group; 1603, 1582, 1508, 1481, m., s., C-C stretch
in phenyl group; 1453, w., s., C-H bend in ethylene grouo;
1429, w., s., para-substituted benzene; 1389, w., s., C-C
stretch in phenyl-aldehyde group; 1368, w.,., ., C-C stretch in
ethylene group; 1324, m., s., asymmetric C-C stretch in vinyloxy
group; 1261, s., s., symmetric C-C stretch in vinyloxy group;
1230, w., s., phenyl C-0 stretch in phenyl ether; 1202, s., s.,
vinyl C-0 stretch in vinyloxy group; 1163, m., m., aliphatic
C-0 stretch in ethoxy group.
5. 2-(2-Vinyloxy)ethoxystyrene.--3067, m., m., asymmetric
C-H stretch of beta hydrogens in vinyloxy group; 3030, m., m.,
symmetric C-H stretch of beta hydrogens in vinyloxy group; 2924,
s., s., asymmetric C-H stretch in ethylene group; 2874, s., s.,
synmetric C-H stretch in ethylene group; 1639, 1618, m., m.,
C-C stretch in vinyloxy group; 1597, 1577, 1484, s., s., C-C
stretch in phenyl group; 1449, s., s., C-H bend in ethylene group;
-53-
1412, m., s., C-H stretch in vinyl of styrene group; 1366,
m., s., C-C stretch in ethylene group; 1322, s., s., asymmetric
C-C stretch in vinyloxy group; 1290, s., s., asymmetric C-C
stretch in vinyloxy group; 1241, s., m., phenyl C-C stretch
in phenyl ether; 1199, s., s., vinyl C-0 stretch in vinyloxy
group; 1133, m., m., aliphatic C-0 stretch in ethoxy group.
6. 3-(2-Vinyloxy)ethoxystyrene.--3125, w., s., C-H
stretch of alpha hydrogen in vinyloxy group; 3077, m., s.,
asymmetric C-H stretch of beta hydrogens in vinyloxy group;
2933, s., s., symmetric C-H stretch of beta hydrogens in vinyloxy
group; 2874, w., m., asymmetric C-H stretch in ethylene group;
2817, w., m., symmetric C-H stretch in ethylene group; 1637,
1617, s., s., C-C stretch in vinyloxy group; 1605, 1597, 1582,
1575, 1511, 1484, all s. to m., s., C-C stretch in phenylgroup;
1445, s., s., C-H bend in ethylene group; 1414, w., m., C-H
stretch in vinyl of styrene group; 1366, w., m., C-C stretch
in ethylene group; 1323, s., s., asymmetric C-C stretch in
vinyloxy group; 1287, s., s., symmetric C-C stretch in vinyloxy
group; 1264, 1244, s., s., phenyl C-0 stretch in phenyl ether;
1199, s., s., vinyl C-0 stretch in vinyloxy group; 1172, m., m.,
aliphatic C-0 stretch in ethoxy group.
7. 4-(2-Vinyloxy)ethoxystyrene.--3058, w., s., asymmetric
C-H stretch of beta hydrogens in vinyloxy group; 2924, w., s.,
symmetric C-H stretch of beta hydrogens in vinyloxy group; 1639,
1618, m., s., C-C stretch in vinyloxy group; 1605, 1577, 1511,
w., m., C-C stretch in phenyl group; 1451, m., s., C-H bend in
-54-
ethlene group; 1410, m., m., stretch in vinyl of styrene group;
1370, m., s., C-C stretch in ethylene group; 1325, s., S.,
asynnotric C-C stretch in vinyloxy group; 1285, s., s., symmetric
C-C stretch in vinyloxy group; 1250, 1241, s., s., phenyl C-0
stretch in phenyl ether; 1202, s., s., vinyl C-0 stretch in
vinyloxy group; 1163, m., m., aliphatic C-0 stretch in ethoxy
group.
8. 2-(2-Vinyloxy)ethoxy-8-nitrostyrene.--3125, w., m.,
C-H stretch of alpha hydrogen in vinyloxy group; 3077, w., m.,
asymmetric C-H stretch of beta hydrogens in vinyloxy group;
2985, m., s., syr-etric C-H stretch of beta hydrogens in vinyloxy
group; 2924, s., s., asymmetric C-H stretch in ethylene group;
2865, w., m., symmetric C-H stretch in ethylene group; 1631,
1605, s., s., C-C stretch in vinyloxy group; 1575, 1506, 1493,
s., s., C-C stretch in phenyl group; 1449, m., s., C-H bend
in ethylene group; 1366, s., s., C-C stretch in ethylene group;
1321, m., s., asynmetric C-C stretch in vinyloxy group; 1299,
w., s., symetric C-C stretch in vinyloxy group; 1250, m., s.,
phenyl C-0 stretch in phenyl ether; 1198, s., s., vinyl C-0
stretch in vinyloxy group; 1161, m., s., aliphatic C-0 stretch
in ethoxy grouo.
9. 4-(2-Vinyloxy)ethoxy---nitrostyrene.--3106, m., m.,
asymmetric C-H stretch of beta hydrogens in vinyloxy group; 2924,
m., m., symnetric C-H stretch of beta hydrogens in vinyloxy
group; 2899, s., m., asynnetric C-H stretch in ethylene group;
2857, s.. n.. symmetric C-H stretch in ethylene group; 1621,
m., s., C-C stretch in vinyloxy group; 1600, 1570, 1508, 1490,
-55-
m., s., C-C stretch in phenyl group; 1451, s., s., C-H bend
in ethylene group; 1425, m., m., para-substituted benzene;
1374, s., s., C-C stretch in ethylene group; 1332, m., m.,
asymmetric C-C stretch in vinyloxy group; 1307, s., s., symmetric '
C-C stretch in vinyloxy group; 1248, s., s., phenyl C-0 stretch
in phenyl C-0 stretch in phenyl ether; 1193, s., s., vinyl
C-0 stretch in vinyloxy group; 1171, s., m., aliphatic C-0
stretch in ethoxy group.
10. 2-Ethyloxyethoxybenzene.--3067, w., m., asymmetric
C-H stretch in ethyloxy group; 2985, n., s., symmetrical C-H
stretch in ethyloxy group; 2924, n., s., asymmetric C-H stretch
in ethoxy group; 2874, m., s., symmetrical C-H stretch in
ethoxy group; 1603, s., s., C-C stretch in phenyl group; 1590,
s., s., C-C stretch in phenyl group; 1497, s., s., C-H
deformation in CH2 units; 1453, n., s., asymrretrical CH3 deformation
in ethyloxy group; 1389, w., m., C-C stretch in phenyl group; 1374,
m., s., symmetrical CH3 deformation in ethyloxy group; 1355, m.,
s., unassignedd); 1333, w., b., C-C stretch in phenyl group;
1304, m., n., C-C stretch in phenyl group; 1292, 1274, phenyl-
C-0 stretch in phenyl ether; 1174, m., s., aliphatic C-0 stretch
in ethoxy and ethyloxy groups.
11. 2-(2-Ethyloxy)ethoxybenzaldehyde.--3067, w., m.,
asymmetrical C-H stretch in ethyloxy group; 2976, m., s.,
symietrical C-H stretch in ethyloxy group; 2924, m., s.,
asymmetrical C-H stretch in ethoxy group; 2865, m., s., symmetrical
C-H stretch in ethoxy group; 2762, w., n., C-H stretch in aldehyde
group; 1689, s., s., C-0 stretch in aldehyde group; 1597, 1582,
s., s., C-C stretch in phenyl group; 1484, s., s., C-H deformation
in CH2 units; 1458, s., m., asymmetrical CH3 deformation in
ethyloxy group; 1397, m., s., C-C stretch in phenyl group; 1372,
m., m., symnetrical CH deformation in ethyloxy group; 1353,
w., n., unassignedd); 1302, w., m., C-C stretch in phenyl group;
1287, 1244, s., m., phenyl-C-0 stretch in phenyl ether; 1189,
s., m., bending the ortho-disubstituted benzene; 1163, s., s.,
aliphatic C-0 stretch in ethyloxy and ethoxy groups.
12. 3-(2-Ethyloxy)ethoxybenzaldehyde.--3067, w., m.,
asymmetrical C-H stretch in ethyloxy group; 2985, m., s.,
symmetrical C-H stretch in ethyloxy group; 2933, m., a.,
asyrretrical C-H stretch in ethoxy group; 2874, m., m., syinetrical
C-H stretch in ethoxy group; 2740, w., m., C-H stretch in aldehyde
group; 1704, 1701, s., s., C-0 stretch in aldehyde group; 1597,
1585, s., s., C-C stretch in phenyl group; 1484, s., s., C-H
deformation in CH2 units; 1449, s., m., asymmetrical CH0 deformation
in ethyloxy group; 1389, m., n., C-C stretch in phenyl group;
1376, m., m., syneitrical CH deformation in ethyloxy group;
1355, w., m., unassignedd); 1325, m., n., C-C stretch in phenyl
group; 1290, 1266, s., a., phenyl-C-0 stretch in phenyl ether;
1171, m., m., aliohatic C-0 stretch in ethoxy and ethyloxy groups.
13. 4-(2-Ethyloxy)ethoxybenzaldehyde.--3067, w., m.,
asymmetrical C-H stretch in ethyloxy group; 2976, m., s., symmetrical
C-H stretch in ethyloxy group; 2933, n., s., asymmetrical C-H
stretch in ethoxy group; 2874, m., s., symmetrical C-H stretch in
ethoxy group; 2740. m., m., C-H stretch in aldehyde group; 1692,
1686, s., s., C-0 stretch in aldehyde group; 1603, 1577, s., s.,
-56-
-57-
C-C stretch in phenyl group; 1508, s., s., C-H deformation in
CH2 units; 1451, m., m., asymmetrical CH3 deformation in ethyloxy
group; 1422, m., m., para-disubstituted benzene; 1393, w., m.,
C-C stretch in phenyl group; 1374, w., m., symmetrical CH3
deformation in ethyloxy group; 1355, w., m., unassignedd);
1312, n., s., C-C stretch in phenyl group; 1261, 1235, 1217,
s., m., phenyl-C-0 stretch in phenyl ether; 1163, s., s.,
aliphatic C-0 stretch in ethoxy and ethyloxy groups.
14. 2-(2-Ethyloxy)ethoxystyrene.--3067, w., m.,
asymmetrical C-H stretch in ethyloxy group; 3021, w., m.,
C-H stretch of alpha hydrogens in styrene group; 2976, m., s.,
symmetrical C-H stretch in ethyloxy group; 2933, m., s., asymmetrical
C-H stretch in ethoxy group; 2874, m., s., symmetrical C-H stretch
in ethoxy group; 1629, s., s., C-C stretch in vinyl of styrene
group; 1603, 1577, s., s., C-C stretch in phenyl group; 1486,
s., s., C-H deformation in CH2 units; 1451, s., s., asymmetrical
CH- deformation in ethyloxy group; 1418, n., m., CH2 deformation
in vinyl of styrene group; 1385, w., m., C-C stretch in phenyl
group; 1374, m., m., symmetrical CH3 deformation in ethyloxy
group; 1355, w., m. unassignedd); 1316, m., m., C-C stretch in
phenyl group; 1294, s., n., C-H deformation of alpha hydrogen
in vinyl of styrene group; 1247, s., a., phenyl-C-0 stretch in
phenyl ether; 1190, w., n., bending in ortho-disubstituted
benzene; 1163, m., m., aliphatic C-0 stretch in ethyloxy and
ethoxy groups.
21. 4-(2-Ethyloxy)ethoxystyrene.-3096, w., m.,
asymmetric C-H stretch in ethyloxy group; 3049, w., n., C-H
-58-
'stretch of altha hydrogen in styrene group; 2994, m., s.,
symnetric C-H stretch in ethyloxy group; 2941, m., s., asymmetrical
C-H stretch in ethoxy group; 2882, m., s., syTmetrical C-H
stretch in ethoxy group; 1631, M., m., C-C stretch in vinyl of
styrene group; 1610, s., s., C-C stretch in phenyl group; 1577,
w., m., C-C stretch in phenyl group; 1511, s., s., C-H deformation
in C 2 units; 1456, w., s., asymmetrical CH3 defornation in
ethyloxy group; 1422, w., m., para-disubstituted benzene; 1412,
w., m., CH2 deformation in vinyl of styrene group; 1385, w., m.,
C-C stretch in phenyl group; 1374, w., s., syr-etrical CH3
deformation in ethyloxy group; 1355, w., m. unassignedd); 1304,
w., m., C-C stretch in phenyl group; 1294, C-H deformation of
alpha hydrogen in vinyl of styrene group; 1238, s., s., phenyl-
C-0 stretch in phenyl ether; 1178, s., s., aliphatic C-0 stretch
in ethyloxy and ethoxy groups.
16. 2-(Ethyloxy)ethoxy-0-nitrostyre.--3115, w., s.,
C-H stretch in vinyl of beta-nitrostyrene group; 3086, w., m.,
asynnetrical C-H stretch in ethyloxy group; 2994, m., s.,
synnetilcal C-H stretch in ethyloxy group; 2941, m., s.,
asymmetrical C-H stretch in ethoxy group; 2890, a., s., symmetrical
C-H stretch in ethoxy group; 1637, s., s., C-C stretch of vinyl
in beta-nitrostyrene group; 1605, 1580, s., s., C-C stretch in
phenyl group; 1550, m., b., C-N stretch in beta-nitrostyrene
group; 1524, 1520, 1515, s., s., C-C1 stretch in CC4 (solvent);
1495, m., s., C-H deformation in CH2 units; 1451, s., s.,
asy-retrical Ci3 deformation in ethyloxy group; 1389, w., m.,
C-C stretch in phonyl group; 1377, w, m., symmetrical CH
-59-
deforration in ethyloxy group; 1344, s., Ir., C-N stretch in
beta-nitrostyrene; 1304, m., m., C-C stretch in phenyl group;
1294, m., m., C-H deformation of alpha hydrogen in vinyl of
beta-nitrostyrene; 1258, s., s., heanvl-C-O stretch in phenyl
ether; 1196, m., m., bending in ortho-disubstituted benzene;
1166, n., m., alinhatic C-0 stretch in ethoxy andethyloxy groups.
17. 3-(2-Ethyloxy)ethoxy-3-nitrostyrene.--3125, w., s.,
C-H stretch in vinyl of beta-nitrostyrene group; 3077, w., m.,
asymmetrical C-H stretch in ethyloxy group; 2994, m., s.,
symmetrical C-H stretch in ethyloxy group; 2941, m., s.,
asymmetrical C-H stretch in ethoxy group; 2882, m., s.,
symmetrical C-H stretch in ethoxy group; 1642, s., s., C-C
stretch in vinyl of beta-nitrostyrene group; 1603, 1580, m., m.,
C-C stretch in phenyl group; 1563, 1550, w., m., C-N stretch
in beta-nitrostyrene; 1527, s., s., C-Cl stretch in CC14 (solvent);
1486, m., m., C-H deformation in CH2 units; 1445, i., m.,
asymmetrical CH3 deformation in ethyloxy group; 1391, w., m.,
C-C stretch in phenyl group; 1376, w., n., symmetrical CH
deformtion in ethyloxy group; 1348, s., s., C-N stretch in
beta-nitrostyrene; 1318, w., m., C-C stretch in phenyl group;
1299, m., s., C-H deformation of alpha hydrogen in vinyl of
beta-nitrostyrene; 1274, s., s., phenyl-C-0 stretch in phenyl
ether; 1232, m., m., C-C1 stretch in CC14 (solvent); 1178,
m., m., aliphatic C-0 stretch in ethoxy and ethyloxy groups.
18. 4- (2-Ethyloxy)ethoxy-8-nitrostyrene.--3115, w., m.,
C-H stretch in vinyl of beta-nitrostyrene group; 3040, w., m.,
-60-
asynietrical C-H stretch in cthyloxy group; 2976, n., s.,
syzetrical C-H stretch in othyloxy group; 2924, m., s.,
asymmetrical C-H stretch in ethoxy group; 2874, m., s.,
syTnetrical C-H stretch in ethoxy group; 1634, s., a., C-C
stretch in vinyl of beta-nitrostyrene grouo: 1605, 1572, s., a.,
C-C stretch in phenyl group; 1546. m., b., C-N stretch in
beta-nitrostyrene; 1522, s.,., ., C-Cl stretch in CC14 (solvent);
1508, C-H deformation in CH2 units; 1453, m., s, asymmetrical
CH3 deformation in ethyloxy groip; 1425, m., s., para-disubstituted
b-enzen; 1385, w., m., C-C stretch in phenyl group; 1374, w., m.,
syretrical CH deformation in ethyloxy group; 1350, s., s.,
C-N stretch in beta-nitrostyrene; 1309, m., s., C-C stretch in
phenyl group; 1294, w., s., C-H defornation of aloha hydrogen
in vinyl of beta-nitrostyrene; 1255, s., m., phenyl-C-0 stretch
in phenyl ether; 1238, m., m., C-C1 stretch in CC14 (solvent);
1174, s., s., aliphatic C-0 stretch in ethoxy and ethyloxy
groups.
D. Iblar Fcfraction and Exaltation of -blar Pefraction.--The
values for the experimentally determined molar refractions were
a by-product in the dipole moment determination. As such, both
for solids and liquids, all of the experimental determinations
were made at the san terperaturc, 30.0oC. The calculations
were executed according to the methods of Vogel (17) and
Eisenlohr (18). The values of the atomic and group parameters
used in these calculations were as follows:
Quantity
Carbon atom
IHydrogen atom
Oxygen atom carbonyll)
Cxygen aton (other)
Carbon-carbon double bond
Nitro group (aromatic)
The results of these determinations are
and 4.
Value of Parameter
Vogel Eisenlohr
2.591 2.418
1.028 1.100
2.211 2.211
1.764 1.643
1.575 1.733
7.30 7.30
tabulated in Tables 3
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-62-
TABLE 3
TABULATION OF MOLAR rEFRACTION DATA
FOR VINYLOXY COMPOUNDS
Compound
Calculated
Found
Vogel Eisenlohr
2-Vinyloxyethoxy-
banzene
2- (2-Vinyloxy)ethoxy-
1-nzaldehyde
3- (2-Vinyloxy)ethoxy-
benzaldehyde
4- (2-Vinyloxy)ethoxy-
benzaldehyde
2-(2-Vinyloxy)ethoxy-
styrene
3- (2-Vinyloxy)ethoxy-
styrene
4-(2-Vinyloxy)ethoxy-
styrene
2- (2-Vinyloxy)e thoxy-t
P-nitrostyrene
4- (2-Vinyloxy)ethoxy-
P-nitrostyrene
48.07
52.88
52.88
52.88
56.89
56.89
56.89
63.16
63.16
47.60
52.23
52.23
52.23
56.37
56.37
56.37
62.57
62.57
48.33
55.08
54.26
56.22
59.14
58.37
58.66
66.35
71.40
Exaltation
Vogel Eisenlohr
0.26 0.73
2.20 2.85
1.38 2.03
3.34 3.99
2.25 2.77
1.48 2.00
1.77 2.29
3.19 3.78
8.24 8.83
-63-
TABLE 4
TABULATION OF MOLAR REFRACTION DATA
FOR ETHYLOXY COMPOUNDS
Compound
Calculated
Found
Vogel Eisenlohr
2-Ethyloxyethoxy-
benzene
2- (2-Ethyloxy)ethoxy-
benzaldehyde
3-(2-Ethyloxy)ethoxy-
benzaldehyde
4- (2-Ethyloxy)ethoxy-
bcnzaldehyde
2- (2-Ethyloxy)ethoxy-
styrene
4- (2-Ethyloxy)ethoxy-
styrene
2- ( 2-Ethyloxy)ethoxy-
B-nitrostyrene
3- (2-Ethyloxy)ethoxy-
0-nitrostyrene
4-(2-Ethyloxy)ethoxy-
3-nitro styrene
48.56
53.36
53.36
53.36
57.37
57.37
63.64
63.64
63.64
48.0?
52.69
52.69
52.69
56.83
56.83
63.03
63.03
63.03
49.95
54.99
54.71
55.97
59.63
60.34
73.88
73.98
77.58
Exaltation
Vogel Eisenlohr
1.39 1.88
1.63 2.30
1.35 2.02
2.61 3.28
2.26 2.80
2.97 3.51
10.24 10.85
10.34 10.95
13.94 14.55
CHAPTER III
DISCUSSION OF PESULTS
Preparation of the Co rounds
For the nost part, the primary objectives of this investigation
have been successfully realized. With the exception of 3-(2-vinyloxy)-
ethoxy-B-nitrostyrone (which has not as yet been successfully
prepared) and 3-(2-ethyloxy)etho:ystyrcnc (which was prepared, but
not in a pure state),' the nuclear magnetic resonance spectra, the
infrared spectra, and the elemental analyses of the confounds were
in agreement with the structures proposed. The yields of the
various compounds, which will be discussed in nore detail below,
are quite respectable, and are the yields of the conmounds in a
state of hiLg purity. De to the relatively high boiling points
of these compounds, no assay of their purity by the techniques
of vapor phase chromatography was attennted.
A. Previously Prepared Cornounds.--A comparison in the
yields reported for those compounds prepared by the old "wt"
method with the yields obtained for the same compounds prepared
by the new "dry" nrthod is presented in tabular form in Table 5,
where the quantity "Per Cent Increase" has been calculated by
the expression:
Per Cent Increase
=, er cEat viold (new method) ner cent yield (old method) 100.
per cent yield (old nethod)
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TABLE 5
COMPARISON MI YIELDS
OF SYNTHETIC ITIIODS
Compound Per Cent Yield Per Cent Increase
(Old lethod) (New Method)
2-Vinyloxyethoxy- 21.00 60.00 185.7
benzene
2-(2-Vinyloxy)ethoxy. 31.53 73.95 134.6
benzaldehyde
3-(2-Vinyloxy)ethoxy- 42.46 82.11 93.38
benzaldehyde 63.64* . .*
4-(2-Vinyloxy)ethoxy- 18.70 80.74** 331.8
benzaldehyde
Solid modification, not previously reported, no comparison possible.
This yield is of crystalline solid; the reported yeild from the old
method was based on liquid, although it was reported that the liquid
crystallized on standing.-
-65-
-66-
The advantage of thn nr method seems quite apparent.
B. Styrenes.-The yields of these compounds are as follows:
2-(2-vinyloxy)ethoxystyrene: 36.34 oer cent; 3-(2-vinyloxy)-
ethoxystyrene: 31.80 per cent; 4-(2-vinyloxy)ethoxystyrene:
49.77 Der cent; 2-(2-ethyloxy)ethoxystyrene: 32.69 per cent;
and 4-(2-ethyloxy)ethoxystyrene: 42.59 per cent. These are
not particularly high yields. There are probably two reasons
for these coaparitively low yields: first, it has been shown
in this laboratory (19, 20) that the Wittig (14) reaction does
not go to completion; and second, styrenes are known to undergo
a facile therral polynerization (21-27). A distillation,
conducted at a temperature sufficiently elevated to allow
separation of the styrene and the parent aldehyde, resulted
in a large amount of polymeric residue in the distillation
flask. The higher the temperature and pressure (the lower
the vacuum), the more efficient the separation and the more
polymeric residue. This fact, coupled with a close similarity
in boiling points, is the main reason that 3-(2-ethyloxy)-
ethoxystyrene was not prepared in a pure state. Various
chroratographic techniques for the purification of this compound
are under investigation at the Dresent time.
C. Beta-Nitrostyre-es.--As far as the 2-vinyloxyethoxy-
8-nitrostyrenos are concerned, the synthetic procedure used
was extremely bad; that these compounds were formed at all is
surprising, that they were isolated in as high yields as reported
is even nore so. The use of low temperature in the final stage
-67-
of this method undoubtedly diminished the rate of vinyl ether
hydrolysis. The use of an inverted addition order (adding the
neutralizing hydrochloric acid solution to the basic reaction
mixture, so that there would be no excess of acid solution to
catalyze the hydrolysis) was investigated. However, under these
more ideal conditions, the desired compounds could not be
isolated. For this practical reason the reported preparative
methods, with their disadvantages, were used. In the
2-ethyloxyethoxy-B-nitrostyrenes, since there is little danger
of a similar hydrolysis of the ethyl group, under the same
reaction conditions, this method is satisfactory. The reason
that the yields were no higher in these compounds is probably
due to the reactivity of the polar beta-nitrostyrene group,
especially towards polymerization. The mother liquors from
the recrystallizations of these compounds always contained
dark, viscous oils or gucry amorphous solids, indicating the
presence of polymeric material.
Physical Measurenents
In order to obtain a check on the accuracy of the method
used to determine the dipole moments, the dipole moment of a
rigorously purified sample of anisole was determined. The
experimentally determined value of 1.25 D (in benzene at 30C.)
was in excellent agreement with the value of anisole quoted
by Weissberger (28) of 1.25 D and in good agreement with
Lumbroso's value (29) (in benzene at 200C.) of 1.28 D. Thus
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it was judCgd that this nothod is satisfactory for the desired
decree of accuracy.
No definite quantitative conclusions can be drawn front
these data until nodol compounds can be synthesized and their
dipolo nozents determined in a syster.atic manner, so as to arrive
at theoretical values for the dipole moments of these compounds.
However, so-e qualitative comparisons with analogous cornounds,
the dipole nonents of which are reported in the literature,
can be made.
1. cDnzeno.--Lunbroso (29) determined the dipole
moment of phenol (in benzene solution at 200C.) to be 1.47 D
and that of anisole (benzene, 200C,) to be 1.28 D. The value
of the dipole moment of phenetole, according to Li (30)
(benzene, 25oC.) was stated as 1.0 D. The dipole moments of
2-vinylo:ycthorybenzene and 2-otiylo::yethoxybenzene, determined
in this investigation (benzene, 300C.) were found to be 1.78 D
and 1.91 D, respectively. They are of the sam order of
nagnitude as the other values for unsubstituted phenyl alkyl
ethers. The lower value for the vinyloxy coemound could be
due to a contribution of the ring form, similar to IV (p. 6)
or to a contribution of the linear form, similar to III (p. 4).
The infrared absorption spectrum of 2-vinyloxyetho:xybenaene
exhibits both of the two peaks at 1639 cm1 and 1621 cnml, as
well as chowing no appreciable shift of the 8.32 micron (1199 cn-l)
peak, indicating that the ring form (IV) does not contribute
to the structure of the compound; it is compatable with the linear
form (III). On the other hand, a comparison of the ultra-violet
-69-
absorption spectra of the vinyloxy and ethoxy corapounds shows
a considerable shift in the short wavelength region, suggesting
that there is a contribution of the ring form. That this shift
is not due to a linear form contribution, and that the spectral
shift is not due to the difference in the position of the
absorption maxima of the vinyloxy group and the ethyloxy group,
will be discussed in the following section. The interpretations
of the various physical properties seem to give conflicting
indications as to the structure of these compounds, and therefore
no conclusions can be reached concerning an interaction of the
type proposed in these compounds.
2. Aldehydes.--In 2-(2-vinyloxy)ethoxybenzaldehyde the
ring is effectively prevented from being formed by the large
amount of steric hinderance afforded by the ortao-aldehyde
groW. Thus only linear forms should contribute, and the
physical properties of this compound and the physical properties
of 2-(2-ethyloxy)ethoxybenzaldehyde should be somewhat similar.
This prediction is borne out quite well by the physical properties
that have been determined for these compounds. The dioole
moments of 2-(2-vinyloxy)ethoxybenzaldehyde and 2-(2-ethyloxy)-
ethoxybenzaldehyde are 4.69 D and 4.49 D, respectively, which
represents a difference of only 0.20 Debye units and are somewhat
similar to the values cf the dipole moment of 2-rothoxybenzaldehyde,
reported by Curran (31) as 4.21 D (benzene, 250C.) and by
LuDbroso (32, 33) as 4.19 D (benzene, 200C.).
The similarity in the physical properties of 2-(2-vinyloxy)-
ethoxybenzaldehyde and 2-(2-,ethyloxy)ethoxybenzaldehyde is also
-70-
displayed in their infrared absorption spectra. Thus the
carbon-oxygen stretching absorption peak occurs at the same
wavenunber in both the vinyloxy compound (1689 cm-1) and the
ethyloxy compound (1689 cn"l). Also the infrared spectrum of
the vinyloxy compound exhibits the two peaks at 1639 cr-1 and
1621 em" attesting to the fact that the ring form does not
contribute to the structure of this compound. Thus the ultra-
violet spectra of these two compounds would be expected to be
quite similar. Inspection of Figure 2 (p. 41) show this to
be the case. Also the difference between the molar exaltation
of 2-(2-vinyloxy)ethoxybenzaldehyde (2.20; Table 3, p. 62)
and 2-(2-ethyloxy)ethoxybonzaldehyde (1.63; Table 4, p. 63)
is only 0.57.
In 3-(2-vinylory)ethoxybenzaldehyde, while there is no
steric hindcrance to the formation of the ring, the contribution
of a phenolic oxonium ion form, analogous to II (p. 4) is
relatively minor, for the phenolic oxygen atom and the aldehyde
group are not suitably located on the benzene ring as to be in
mutual conjugation. The dipole amments of 3-(2-vinyloxy)-
ethoxybenzaldehyde (3.13 D) and 3-(2-ethyloxy)ethoxybenzaldehyde
(3.45 D), while not as similar as the previous compounds, differ
by only 0.32 Debye units. Thus the other physical properties
would be expected to be somewhat similar, as in the previous case.
The difference in the position of the carbon-oxygen
stretching absorption peak of the.aldehyde group in the infrared
spectra of 3-(2-vinyloxy)othoxybenzaldehyde (1695 cmrl) and
-71-
3-(2-ethyloxy)etho:ybenzaldehyde (1701 clm1), 6 cr-1, is close
to the accuracy with which the spectral positions can be determined
on the chart paper (plus or minus 0.01 microns; plus or minus
3 cm"1 in this range of :avonu:ibers). The infrared spectrum of
the vinyloxy compound exhibits both of the absorption peaks
at 1639 cm1 and 1621 cml1 and shows no appreciable shift in
the peak at 1199 cn"1 (8.34 microns).
Inspection of the ultra-violet spectra of these compounds
shows that, while there is a great deal of similarity in the
spectra, a slight difference is becoming apparent in the short
wavelength end of the spectra. The molar exaltations of these
two compounds are nearly identical (1.38 and 1.35, for the
vinyloxy and the ethyloxy compounds, respectively). In
conclusion, it may be stated that the physical properties of
3- (2-vinyloxy)ethoxybenzaldehyde and 3-(2-ethyloxy)ethoxy-
benzaldehyde indicate that these two compounds probably have
the same type of structure, with respect to the type of
interaction postulated, and that the ring form of the type
postulated could, at the most, have only a slight contribution
in the structure of 3-(2-vinyloxy)ethoxybenzaldehyde.
In 4-(2-vinyloxy)ethoxybencaldehyde, since the two
substituents on the benzene ring are in a position arn to
each other, there is no steric hinderance to the formation of
the ring, and the two groups are in conjugation. Thus, if the
ring is formed as postulated, a considerable difference in the
physical properties of -(2-vinyloxy)ethoxybenzaldehyde and
-72-
4-(2-ethyloxy)othoxybenzaldehyde would be predicted. In considering
the dipole moments of those two compounds, it is found that the
dipole norent of the vinyloxy compound (4.08 D) is smaller than
that of the ethyloxy compound (4.48D) by 0.40 Debye units. This
is a reversal of the situation in the 2-(2-alkyloxy)cthoxy-
benzaldehyde series, where the nonent of the vinyloxy compound
was larger than that of the ethyloxy compound. This difference
of 0.40 Debye units is greater than that in the preceding
3-(2-allyloxy)ethoxybenzaldehyde series, and is certainly
greater than the experimental error in the determination of
these properties.
This apparently anomolous difference in the dipole noments
of these two compounds may indicate that the postulated ring
form has a significant contribution to the structure of
4-(2-vinyloxy)ethoxybenzaldchyde. If this is the case, a
considerable difference would be expected in the position of
the aldehyde carbon-oxygen stretching absorption peak in the
infrared spectra of these compounds. The observed positions
of this peak in the saectra of 4-(2.viLiyloxy)etho:ybcnzaldehyde
(1704 cm1 ).and 442-ethyloxy)ethorybenzaldehydo (1692 cn-1
and 1686 cn-1 split from a central value of 1689 or 1 -- which,
incidently, is the position in both of the 2-isomers) differ by
15 cn" a value which is greater than the error in the deter-
iination of the position of the peak.
Since both of the peaks at 1639 cn-1 and 1618 cm-1 are
present in the infrared spectrum of 4-(2-vinyloxy)ethoxy-
benzaldehyde, the ring is obviously not formed to the exclusion
-73-
of the linear form. A semi-quantitative study was undertaken
on the amplitude of these peaks. Since the spectra obtained were
in per cent transmittance, the reciprocal of the transmittance
values of the maxima were subtracted from the reciprocal of the
transmittance values of an extrapolated base line. The ratio
of the peak height in absorbance units of the 6.08 micron peak
(1639 cml-) to that of the 6.18 micron peak (1621 cml) in the
same units was then calculated. This order was chosen for, to
the extent that the ring would be formed, the 6.08 micron peak
would diminish. This ratio was calculated for each of the three
isomeric 2-vinyloxyethoxybenzaldehydes, and was found to be:
2-isorer; 0.553; 3-isomer: 0.512; 4-isomer: 0.394. Since it
was concluded that in the case of the 2-isomer only the linear
form was present, the fraction of the contribution of this form
would be 1.00. Normalizing these ratios so that the ratio of
the 2-isomer is 1.00, the following new ratios are obtained:
2-isomer: 1.00; 3-isomer: 0.942: 4-isomer: 0.713, which, when
converted into per cent, become: 2-isomer: 100 per cent (linear
form); 3-isomer: 94 per cent (linear form); and 4-isomer: 71
per cent (linear form).
The above study was admittedly only semi-quantitative;
however, it indicates that, in the case of the 3-isomer, only
about 6 per cent of the actual structure of this compound could
be contributed by the postulated ring form. Thus it is not
difficult to explain why the study of the physical properties
of this compound failed to do more than indicate a possibility
of a small contribution of the postulated ring form. The
prediction of this study of about a 29 per cent contribution
by the postulated ring fonrm to the structure of 4-(2-vinylo:y)-
cthoxybcnzaldchyde should be capable of verification (or at
least support) by a study of the reminder of the physical
properties of this compound.
A comparison of the ultra-violet absorotion spectra of
4-(2-vinyloxy)ethoxybenzaldehyde and 4-(2-ethyloxy)ethoxy-
benzaldehyde (Figure 4, p. 43) chows a considerable shift in
the position of the short wavelength peak. The position of
the raxiia in the ethyloxy compound is 197.0 nillimicrons and
that of the vinyloxy compound is 205.5 nillinicrons, a shift
of 8.5 millimicrons, a value considerably greater than the
experimental error in the determination of the position of
these naxina. 1breover, the shift is in the predicted (cf. p. 8)
direction, indicating that, as far as this neak is concerned,
at least, the vinyloxy coeaound is the low r-energy compound
of the two. Finally, the nolar exaltation of the vinylo:x
compound (3.34) is about 28 per cent greater than that of the
cthyloxy compound (2.61). It is interesting to note that the
value of this increase in molar exaltation (28 per cent) is
quite close to the per cent contribution of the ring form
predicted in the "semi-quantitative study" (29 per cent).
In conclusion it may be 'stated that the study of the
physical properties of 4-(2-vinyloxy)ethoxybcnzaldehyde and
4-(2-ethyloxy)ethoxybenzaldehydo indicated that, for the most
-75-
part, these two compounds have the same type of structure, but
that there probably is a significant contribution of the postulated
ring form to the actual structure of 4-(2-vinyloxy)ethoxybenzaldehyde.
3. Styrenes.--The dipole moments of 4-methylstyrene
(0.38 D) and 3-methylstyrene (0.36 D), determined by Evarard
and Sutton (34), are so close to the value quoted for toluene
(0.37 D) by Gould (35) that some authors (34) feel that the
dipole noment of styrene, itself, within the limits of experimental
accuracy, in indistinguishable from zero. Con~aring this with
the dipole rmoent reported (36) for benzaldehyde (2.75 D), it
would be predicted that, if-there were any contribution at all
of an interaction of the type postulated, it would be of such
ninor importance as to cause differences in the physical properties
of these compounds so small that they would approach the
experimental error of these determinations. In as much as the
physical properties of 4-(2-vinyloxy)ethoxybenzaldehyde gave
the most indicative evidence for the existence of the postulated
interaction, it would be expected that the greatest difference
in the 2-alkyloxyethoxystyrenes in this investigation would
occur in the 4-isomers..
The difference in the dipole moment of 4-(2-vinyloxy) -
ethoxystyrene (2.15 D) and 4-(2-ethyloxy)ethoxystyrene (2.08 D)
is 0.07 Debye units. This value is approaching the experimental
error of the determination and is too small a difference to
use for even a qualitative study of an interaction of the type
postulated. An inspection of the ultra-violet spectra of these
-76-
two compounds (Figure 7, p. 46) shows a small shift in the
short wavelongth end of the spectra. Althourh'the shift is
in the predicted direction (vinyloxy compound absorption maxima
at longer wavelength), its value, 3.0 millinicrons, is approaching
the accuracy with which the position of the maxina, especially
somewhat "rounded" maxima, can be determined from the chart
paper (plus or minus 0.5 millinicrons) and the accuracy of the
instrLent (same value). Thus it nay be stated that, while only
very qualitative conclusions may be reached concerning inter-
actions in these compounds of the type postulated, the strongest
contribution to the actual structure of any of these styrenes
would probably occur in 4-(2-vinyloxy)ethoxystyrene, and even
in this comound such a contribution would probably be
extremely minor, if detectable.
4. Beta-ilitrostyrenes.--If a comparison, similar to
that nade between styrene and benzaldehydo, is iade between
the dipole moment of beta-nitrostyreno (4.51 D, benzene, 25C,.;
4.50 D, benzene, 250C., 4.27 D, dioxane, 250C.; reported by
Vasil/eva et J. (37), Sutton et1a. (38), and Gaebel and Wenzke (39),
respectively) and that reported for benzaldehyde (2.75 D) by
Sryth (36), it would be predicted that the contribution of an
interaction of the type postulated would be stronger in the
more polar be9t-nitrostyrenes than in the aldehydes.
Since the bet-nitrovinyl group would be expected to have
even greater steric requirements than the aldehyde group, and
since it was postulated that the steric requirements of the
-77-
ortho-aldehyde group in 2-(2-vinyloxy)ethoxybenzaldehyde
prevented the formation of the ring and thus any contribution
from an interaction of the type postulated, then it would be
expected that there would be no contribution of this type in
the structure of 2-(2-vinyloxy)ethoxy-B-nitrostyrene. Thus
only the linear form should contribute to the structure of this
co ounr ,nd the physical properties of this compound and those
of 2-(2-ethyloxy)ethoxy-B-nitrostyrene should be quite similar.
The dipole moments of-the vinyloxy compound (5.81 D) and
the ethyloxy compound (5.65 D) are actually quite similar,
differing by only 0.16 Debye units, a difference even smaller
than that encountered in the corresponding aldehydes. No
reported values for the dipole moment of 2-alkyloxy-5-nitrosytrenes
were found in the literature.
The infrared absorption spectrum of 2-(2-vinyloxy)ethoxy-
D-nitrostyrene shows two peaks at 1631 c- and 1605 cm1, as
would be expected. Although those peaks are slightly shifted
with respect to the positions of the corresponding peaks in
2-(2-vinyloxy)ethoxybenzaldehyde, this could well be due to
the solvent effect. 2-(2-Vinyloxy)ethoxybenzaldehyde, being a
liquid, had its infrared spectrum determined as a pure liquid;
2-(2-vinyloxy)ethoxy-P-nitrostyrene, on the other hand, being
a solid had its infrared spectrum determined in carbon
tetrachloride solution. Also, the position of the strong peak
at 1198 cm"1 (8.35 microns) in the infrared spectrum of the
beta-nitrostyrene is not.signific antly shifted from the "normal"
position of 1202 cm-1 (8.32 microns).
-78-
On this basis it would be expected that the ultra-violet
spectra of 2-(2-vinyloxy)ethoxy-P-nitrostyrene and 2- (2ethyloxy)-
B-nitrostyrene would be quite similar. An inspection of
Figure 8, p. 47, show that these two spectra are quite similar.
The only physical property that was determined for these compounds
that showed an anomolous discrepancy was the molar exaltation.
The molar exaltation values for all three isomers of 2-ethyloxy-
ethoxy- -nitrostyreno were very hich; therefore these values
can only be used with great reserve. Thus it may be stated that
2-.-vinyloxy)ethoxy-0-nitrostyree and 2-(2-ethyloxy)ethoxy-0-
nitrostyrenc probably have the same type of structure and that
an interaction of the type proposed does not have any significant
contribution to the structure of 2-(2-vinyloxy)ethoxy--O-
nitrostyrene.
3-(2-Vinyloxy)ethoxy-3-nitrostyrene has not been prepared
as yet and thus no further discussion of this isomer is possible.
So far in this investigation, within any series of
positional isomers, if the physical properties of any isomer
have shown a deviation from those of the remainder of the series,
suggesting the intervention of, and some degree of structural
contribution from, an interaction of the type that has been
postulated, this isomer has been the 4-isomer. This trend would
not only be expected to be continued by 4-(2-vinyloxy)ethoxy-B-
nitrostyrene, but also to be intensified. Thus it would be
predicted that the postulated ring form, IV (p. 6), would show
a stronger contribution to the structure of this compound than
it has shown to th structure of any other.
-79-
The difference between the dipole moment of 4-(2-vinyloxy)-
ethoxy-0-nitrostyrene (5.43 D) and that of -(2-ethyloxy)ethoxy--
nitrostyrene (6.14 D) is 0.71 Debye units. This difference is
even more significant than its value would indicate, for, as
can be seen, the moment of the vinyloxy compound is the lesser,
the reverse of the situation encountered in the 2-isomers
(where the ring did not have a contribution). If this difference
in the dipole moments of these two compounds signifies the
contribution of the ring form to the actual structure of
4-(2-vinyloxy)ethoxy-'-nitarstyrene, as it suggests, the other
physical properties should also show a difference between these
two compounds.
The infrared spectrum of the linyloxy compound exhibits
only one peak in the range 1639-1618 cm-1, and this peak occurs
at 1621 cm"1 (6.17 microns). The "normal" 8.32 micron peak
has been shifted to 1193 ca- (8.38 microns), a shift of 9 cm".
A consideration of the physical properties of 4-(2-vinyloxy)-
ethoxy-&-nitrostyrene that have been discussed up to this point
would certainly suggest not only that the ring form has a
significant contribution to the structure of this compound, but
also that the contribution of the linear form is so small as to
escape detection (no peak was present in the infrared spectrum
of this compound at or near 1639 cm- ). Final, confirmatory
evidence would be expected from the remainder of the physical
properties.
An inspection of the ultra-violet spectra of these two
compounds shows that such is not the case, for the two spectra
-80-
are quite similar. Thus, independently considered, the ultra-
violet spectra would indicate that the structures of the two
compounds would be the sane. The only explanation offered for
the lack of confirnatory evidence in the ultra-violet spectra
is that the change in the electronic structure of the vinyloxy
compound by the proposed interaction produces a change in the
position of a maximum that was outside of the region investigated.
Finally, a consideration of the values of the molar
exaltation of these cormounds shows that, even though the
ethyloxy cormound still has a much larger exaltation than the
vinyloxy compound (13.94 to 8.24, a difference of 5.60), it
was not as Iuch larger than the vinyloxy compound as was the
case in the 2-isomers (ethyloxy: 10.24; vinyloxy: 3.19, a
difference of 7.05). In conclusion it may be stated that the
dipole -oment data suggest that there nay be a contribution by
the ring form preacnt, the infrared data indicates that this is
the only form present, and the ultra-violet data indicates that
this form is probably not present, and the molar exaltation data
indicates almost nothing. Thus, until further investigations
can be carried out on these and related compounds, no definite
conclusions can be reached concerning the structure of
4-(2-vinyloxy)ethoxy-p-nitrostyrene.
5. Other Co.wounds.-An investigation, very similar to
this investigation, is presently underway, the objectives of which
are the preparation and the determination of the physical properties
of a third series of compounds. These compounds include:
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4- (2-vinyloxy)-ethoxyacetophenone, 4- (2-vinyloxy)othoxy-a-
methylstyrene, 4- (2-vinyloxy)ethoxy-a-methyl- -nitrostyrene,
4-(2-ethyloxy)ethoxyacetophenone, 4- (2-ethyloxy)ethoxy-c-
methylstyrene, and 4- (2-ethyloxy)ethoxy-c- nethyl-_-nitrostyrene.
It is hoped that this investigation will finally give the
conclusive evidence for the proposed interaction.
In conclusion one final note should be made concerning the
8.32 micron peak in the infrared absorption spectra of the
2-vinyloxyetho;zbenzaldehydes (cf. p. 3). Since the infrared
spectrum of 4-(2-ethyloxy)ethoxybenzaldehyde did not contain
this peak, the 8.32 0.02 micron peak can be unambiguously
assigned to the (linear) vinyloxy group.
CHAPTER IV
SUI.5'.Ar.Y
2-Vinyloxyethoxybenzene, 2-, 3-, and 4-(2-vinyloxy)-
ethoxybenzaldehyde, 2-, 3-, and 4.(2-vinyloxy)ethoxystyrene,
2- and 4-(2-vinyloxy)ethoxy-P-nitrostyrene, 2-ethyloxyethoxy-
benzene, 2-, 3-, and 4-(2-ethyloxy) ethoxybenzaldehvde,
2- and 4-(2-ethyloxy)ethoxystyrene, and 2-, 3-, and 4-(2-ethyloxy)-
B-nitrostyrene have been prepared. The dipole moment of these
conmounds has been determined. The infrared and the ultra-
violet absorption spectra of these compounds have been obtained.
The molar refraction and the molar exaltation of these compounds
have been determined.
A study of the experimentally determined physical properties
of these compounds has lead to the postulation of an electronic
interaction, in the form of a non-bonded six-membered ring,
similar to that proposed by Butler (40-42) and supported by
Jones (43), Marvel (44), Field (45), and Schuller (46), anong
others. Cram and Kopecky (47) have also proposed an analogous
type of interaction. Evidence for the contribution of this
type of interaction to the structure of 4-(2-vinyloxy)ethoxy-
benzaldehydc has beon gained.
-E2.
BIBLIOGRAPHY
1. G. B. Butler and J. L. Nash, J. AM. Chen. Sec., 72, 2538 (1951).
2. J. L. Nash, "Polymerization Studies of Unsaturated Derivatives
of Beta-Iitrostyrenes," Ph. D. Dissertation, University of
Florida, 1953.
3. G. B. Butler, _. An. Chem. Soc., 27, 482 (1955).
4. E. S. Gould, mechanism m and Structure in Organic Chemistry,"
Henry Holt and Co:apany, New York, New York, 1959, p. 217.
5. E. S. Could ib., p. 201.
6. M. I. Eatuev, E. N. Prilezhaeva, and M. F. Shostakovskii,
BM. aa. sci. U...S., Clsse sci. chg., 1947, 123.
7. M. L. V. Brey, "The Preparation and Properties of Vinyl and
Glycidyl Fluoroethers," Ph. D. Dissertation, University of
Florida, 1956.
8. M. L. Brey and P. Tarrant, J. k,. Chen. Soc., 79, 6533 (1957).
9. C. McKinley, U. S. Pat. 2,533,172, Dec. 5, 1950 to General
Aniline and FilM Corporation (C. J., A5, 3407 [19513).
10. Central Aniline and Film Corporation and C. IcKinley, Brit.
Pat. 630,926, Oct. 24, 1949 (C. A., t4, 4021 [19503).
11. A. Zahorka and K. Weimann, Ibnatsh, L9, 229 (1938) (C. A.,
92, 4415 [19383).
12. R. Paul, s. ch m. Franc (), 1, 971 (1934) (C. A.,
_22, 786 [1935]).
13. A. Kailan and S. Schwebel, oFnajth., 3, 55 (1933) (C. A.,
2L8, 2982 [19341).
14. (a) J. Levisalles, Bull. g. S=. France, 1958, 1021.
(b) U. Schollkopf, An Chem., 7, 260 (1959).
(c) S. Trippett, "Advances in Organic Chemistry," Vol. I,
Intersiience Publishers, Ine., New York, New York, 1960,
pp. 83-102.
-83-
-84-
(d) R. C. Slagel, Illinois Se'innr, Nov. 17, 1961, pp. 92-101.
15. (a) J. Thiele, ar., _a, 1294 (1899).
(b) J. Thiele and 3. Haeckel, Ann., .2, 7 (1902).
16. A. I. Popov and R. D. Holm, _. Phy. Me., 5, 774 (1961).
17. A. I. Vogel, J. r Soc., 1i~8, 1842.
18. F. Eisenlohr, Chen. Zentr. (;), ., 625 (1911).
19. C. F. Hauser, T. W. Brooks, 1M. A. Praynond, and G. B. Butler,
J. rg. (in press).
20. C. F. Hauser, M. L. Miles, and G. B. Butler, J. C e. r,
(in press).
21. K. Kirchner and F. Patat, hkromo. C~m. 251 (1960).
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American Cyanamid Company (_. A., .5, 17967 [1960]).
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(_. _A., ~ 14299 [19593).
24. F. Patat and K. Kirchner Naturwissenschaften, 45, 129
(A. _A., ., 14299 [1958]).
25. J. A. ~alchore, U. S. Pat. 2,745,824, ay 15 1956 to
American Cyananid Company (C. ,A, 5O, 12537 [1956]).
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5052 (1953).
27. J. W. Breitenbach and W. Thury, Anz. Akad. li ss. iJn.
'Moth. -natrw. Klasse, 83, 4 (19467 (_. ., !, 8735 [19493).
28. A. Weissberger (ed.), "Technique of Organic Chemistry," Vol. I;
"Physical Methods of Organic Cheristry," Part II, 2nd Ed.,
Interscience Publishers, Inc., New York, New York, 1949,
p. 1614.
29. H. Lunbroso, L)1. soA. S=. Franc, 1955, 643 (9. A., 49,
11340 [1955]).
30. N. C. C. Li, J. a=.* PILa., 2, 1068 (1939) L(. A., Z4, 297 [1940]).
31. C. Curran, J. An. Chen. Soc., 67, 1835 (1945).
32. H. Lumbroso and P. Rfupf, Bull. ,ac. chim. Fr-ane, 1950,
371 (C. A., 44, 7106 [19591TT
-85-
33. H. Luwbroso, A. fac. ~ i. Toulouse, ci. nath,
et sci. hys., 14, 9 (1950) (L. A., Z8, 5783 1195j47.
34. K. B. Everard and L. E. Sutton, Nature, 1,62 104 (1948)
(C. A., 42, 8037 [1948]).
35. E. S. Could, 2. cit., p. 60.
36. C. P. Smyth, "Dielectric Constant and ;blecular Structure,"
The Chemical Catalog Corpany, Inc., New York, lieu York,
1931, p. 196.
37. V N. Vasileva, V. V. Perskalin, and V. G. Vasil^ev,
8)~" a. SSj SS, 14, 620 (1960) C. A. 12780
38. K. B. Everard, L. Kumar, and L. E. Sutton, J. Chem. SOc.
1951, 2807.
39. H. L. Goebel and H. H. Wenzke, J. Am. Chen. .So, 60, 697
(1938).
40. G. B. Butler and F. T. Inglcy, jid., 73, 894 (1951).
41. G. B. Dutler and R. J. Angelo, ibid., 22, 3128 (1957).
42. G. B. Butler, A. Cranshaw, and W. L. Miller, ibid., 80,
3615 (1958).
43. J. F. Jones, _. Pol~yer t ., 3, 7 (1958).
44. C. S. .~rvel and J. K. Still, J. . Ch~ag.so. 80,
1740 (1958).
45. N. D. Field O. _. D Chcn9., 1006 (1960).
46. W. H. Sohuller, J. A. Price, S. T. Tbore, and W. M. Thomas,
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2748 (1959).
BIOGRAPHICAL SKETCH
Ronald E. Tho-pson was born on December 11, 1931, in
St. Augustine, Florida. He graduated from Ketterlinus High
School, St. Augustine, Florida, in 1949. He spent three years,
eleven months, and ten days in the defense of the country during
the Korean Conflict, being stationed in Texas and the Philippine
Islands. He attended the University of Florida, from which he
graduated in 1958 with the degree of Bachelor of Science in
Chemistry. He attended Wayne State University, Detroit, Michigan,
as a Parke, Davis, and Company Research Fellow, from which he
graduated in 1960 with the degree of Master of Science. He
returned to the University of Florida as a graduate research
assistant under Dr. G. B. Butler.
The author is a member of Gamma Sigma Epsilon, National
Chemistry Honorary Fraternity, and served as President of the
Beta Alpha Chapter, University of Florida, from 1961 to 1962.
He is a past Vice-President of the University of Florida Section,
Student Affiliates of the the American Chemical Society. He
is a omeber of the American Chemical Society and The National
Rifle Association.
The author is married to the former Roslyn Berman and is
the father of one child, David Earl. His hobbies are photography,
architecture, music, stanp collecting and money collecting.
-86-
This dissertation was prepared under the direction of the
chairman of the candidate's supervisory committee and has been
approved by all members of that committee. It was submitted
to the Dean of the College of Arts and Sciences and to the
Graduate Council, and was approved as partial fulfillment of
the requirements for the degree of Doctor of Philosophy.
August 11, 1962
Dean, CHo-lge of Artsand Sciences
Dean, Graduate School
Sueyisory Comittee:
Chairman
33 409
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