Reactivity of benzophenone O-vinyloxime

Article abstract of DOI:10.1023/B:RUJO.0000010559.50645.5b

Benzophenone O-vinyloxime readily takes up bromine and hydrogen chloride to give benzophenone O-(1,2-dibromoethyl)oxime and benzophenone O-(1-chloroethyl)oxime, respectively. Its reactions with methanol, trifluoroacetic acid, and acetic acid lead to formation of the corresponding O-(1-methoxyethyl), O-(1-trifluoroacetoxyethyl), and O-(1-acetoxyethyl) derivatives. Slow heating of the title compound induces its decomposition with formation of benzophenone as the major product; fast heating leads to a complex mixture of products containing benzophenone, benzophenone imine, and acetaldehyde.

Full text of DOI:10.1023/B:RUJO.0000010559.50645.5b

Russian Journal of Organic Chemistry, Vol. 39, No. 10, 2003, pp. 1429 1435. Translated from Zhurnal Organicheskoi Khimii, Vol. 39, No. 10, 2003,
pp. 1501 1507.
Original Russian Text Copyright
2003 by Zaitsev, Shmidt, Vasil’tsov, Mikhaleva, Morozova, Ushakov, Afonin, Il’icheva.
Dedicated to Full Member of the Russian Academy of Sciences
B.A. Trofimov on the 65th Anniversary of His Birth
Reactivity of Benzophenone O-Vinyloxime
A. B. Zaitsev, E. Yu. Shmidt, A. M. Vasil’tsov, A. I. Mikhaleva, L. V. Morozova,
I. A. Ushakov, A. V. Afonin, and L. N. Il’icheva
Favorskii Irkutsk Institute of Chemistry, Siberian Division, Russian Academy of Sciences,
ul. Favorskogo 1, Irkutsk, 664033 Russia
fax: (3952)419346; e-mail: mikh@irioch.irk.ru
Received June 27, 2003
Abstract Benzophenone O-vinyloxime readily takes up bromine and hydrogen chloride to give benzo-
phenone O-(1,2-dibromoethyl)oxime and benzophenone O-(1-chloroethyl)oxime, respectively. Its reactions
with methanol, trifluoroacetic acid, and acetic acid lead to formation of the corresponding O-(1-methoxy-
ethyl), O-(1-trifluoroacetoxyethyl), and O-(1-acetoxyethyl) derivatives. Slow heating of the title compound
induces its decomposition with formation of benzophenone as the major product; fast heating leads to a com-
plex mixture of products containing benzophenone, benzophenone imine, and acetaldehyde.
The chemistry of vinyl ethers, whose groundwork
was laid by A.E. Favorskii [1], extensively developed
in the midtwentieth century, when most fundamental
transformations of these compounds were discovered
their wide application in the synthetic practice. Diaryl
ketone O-vinyloximes, which have recently become
available [16], are stable to storage and heating. These
properties, in addition to high yields of these com-
pounds, make them promising monomers and inter-
mediate products, as well as model structures for
studying the reactivity of the O-vinyloxime fragment.
In the present work we examined chemical pro-
perties of the simplest representative of diaryl ketone
O-vinyloximes, benzophenone O-vinyloxime (I) with
the goal of elucidating whether reactions typical of
conventional vinyl ethers could be used for chemical
modification of diaryl ketone O-vinyloximes, as well
as of obtaining on that basis new intermediate prod-
ucts for organic synthesis.
(see [2, 3] and references therein). Later on, the most
important studies concerning quantitative estimation
of the reactivity of vinyl ethers and effects of func-
tional substituents were performed by B.A. Trofimov
and co-workers [4, 5]. The results of these studies
gave rise to extensive application of functionalized
vinyl ethers in organic synthesis, specifically in
the preparation of polymers possessing various useful
properties [4, 6].
We recently reported on the synthesis from ketone
oximes and acetylene of ketone O-vinyloximes [7]
and amide O-vinyloximes [8, 9] which can formally
be regarded as vinyl ethers. These derivatives contain
a highly reactive vinyl group directly attached to
an oxime fragment, which extends the range of pos-
sible chemical transformations as compared to con-
ventional vinyl ethers. For example, O-vinyloximes
were used in the synthesis of trifluoroacetyl deriva-
tives [10, 11] and new unsaturated heterocyclic com-
pounds of the pyrrole [12 14], hydroxydihydropyrrole
Oxime I readily reacted with bromine at room
temperature (reaction time 5 min) to afford 78% of
benzophenone O-(1,2-dibromoethyl)oxime (II):
[
12, 14], 3H-pyrrole [14, 15], oxazole [10], and oxa-
diazole series [9]. However, chemical and thermal
instability of O-vinyloximes derived from dialkyl and
alkyl aryl ketones [7] remains a serious obstacle to
An analogous reaction pattern is typical of such
representative of dialkyl ketone O-vinyloximes as
1
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ZAITSEV et al.
methyl isopropyl ketone O-vinyloxime (III). In this
case, an appreciable amount of tars is formed, presum-
ably as a result of bromine-initiated polymerization
of initial O-vinyloxime III.
1-Haloethyl ethers derived from O-vinyl ethers are
also known to be unstable [17]. The greater stability
of benzophenone oxime O-(1-chloroethyl) ether to
hydrolysis also follows from the fact that, unlike
conventional -chloro ethers [17], it does not fume
on exposure to air.
Benzophenone O-vinyloxime (I) also exhibits
a lower reactivity (as compared to vinyl ethers [17])
toward carboxylic acids and alcohols:
Strong tarring was also observed in the bromina-
tion of conventional vinyl ethers. This process can be
avoided by adding vinyl ether to bromine without
a solvent, as was demonstrated for the first time by
M.F. Shostakovskii [17]. The relatively ready and
effective bromination of benzophenone O-vinyloxime
may be explained by the presence in molecule I of
bulky benzene rings which hinder polymerization due
to their electronic effect and steric factor.
VI, R = Ac; VII, R = CF CO; VIII, R = Me.
3
For example, heating of equimolar amounts of
compound I and acetic acid at 60 C over a period of
0
.5 h leads to only 12% conversion of the substrate.
Additional heating of the reaction mixture for 3 h at
0 C increases the yield of benzophenone O-(1-acet-
oxyethyl)oxime (VI) to 40%. The rate of addition of
a stronger acid (trifluoroacetic) is higher, and almost
complete conversion of benzophenone O-vinyloxime
8
No addition at the double bond occurred in the
reaction of oxime I with iodine. The process is
likely to include a complex combination of various
reactions whose products give rise to a complicated
(
I) in the reaction with trifluoroacetic acid at 60 C
is achieved in 0.5 h. However, the formation of the
target product, benzophenone O-(1-trifluoroacetoxy-
ethyl)oxime (VII), is accompanied by side processes
which are likely to involve acid-catalyzed transforma-
tions of the O-vinyloxime group.
The addition of alcohols to oxime I also follows
the Markownikoff rule. In the reaction of I with
boiling methanol (15 min) in the presence of 1 % of
trifluoroacetic acid (with respect to I), the substrate
conversion was as low as 15%. Raising of the amount
1
H NMR spectral pattern. Likewise, polymerization
processes predominated in similar reactions with vinyl
ethers [17]. Probably, in the iodination of ketone
O-vinyloximes, polymerization is accompanied by
redox reactions involving iodine and oxime groups.
The reaction of benzophenone O-vinyloxime (I)
with dry hydrogen chloride afforded exclusively the
corresponding Markownikoff adduct, benzophenone
O-(1-chloroethyl)oxime (V), in 87% yield.
of CF COOH to 30%, other conditions being equal,
3
leads to complete transformation of I into benzo-
phenone O-(1-methoxyethyl)oxime (VIII). However,
owing to side processes with particpation of the
O-vinyloxime functionality the yield of oxime ether
1
*
VIII does not exceed 26% (according to the H
1
According to the H NMR data, no further reaction
NMR data). A probable reason for the lower reactivity
of diaryl ketone O-vinyloximes relative to vinyl ethers
is partial binding of protons of the acid catalyst by
lone electron pair of the oxime group. It should be
noted that no disproportionation occurs during the
addition of alcohols and carboxylic acids to oxime I.
of adduct V with hydrogen chloride was observed.
The high selectivity was also noted for reactions of
vinyl ethers with hydrogen chloride [17]. Adduct V
neat) is relatively stable at room temperature (over
a week), while in CDCl it undergoes appreciable dis-
(
3
1
proportionation even in 12 h ( H NMR data).
Trifluroacetylation of benzophenone O-vinyloxime
(I) was performed by the procedure reported in [11]
for analogous reaction with dialkyl ketone O-vinyl-
_
___________
*
As in Russian original. Publisher.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 39 No. 10 2003

REACTIVITY OF BENZOPHENONE O-VINYLOXIME
1431
oximes (room temperature, reaction time 2.5 h). Since
trifluoroacetylation product IX cannot be distilled, it
was isolated by the procedure used previously [18] in
the trifluoroacetylation of vinyl ethers: the target
product was separated via dissolution in hexane.
However, the isolated material contained only 25%
tion of the oxime nitrogen atom in I was observed:
The H signals from the vinyl group almost did not
1
shift downfield. A weak nucleophilic character of the
nitrogen also follows from the lack of its quaterniza-
tion on mixing of benzophenone O-vinyloxime (I)
with 2 equiv of methyl iodide at room temperature.
Even after a month, the mixture contained only the
initial compounds.
1
of IX ( H NMR data); protons at the double C C
bond in IX give rise to signals at 8.30 and 6.27 ppm
3
with a coupling constant J of 12.4 Hz, which in-
Our attempt to effect radical addition of 1-butane-
thiol to oxime I was unsuccessful. At 80 C (8 h),
the reaction yielded benzophenone (XI) and polymeric
products which were characterized by broadened
dicates trans substitution at the -carbon atom of the
vinyl group.
1
signals in the H NMR spectrum at 7.10 7.35, 2.30
2
.70, 1.45 1.70, 1.30 1.45, and 0.80 0.95 ppm.
1
We failed to detect by H NMR spectroscopy stable
carbocations which could be formed via protonation
of the O-vinyl gruup by strong acids (CF SO H,
3
3
FSO H, 70 C), presumably because of positive
charge transfer to the heteroatoms:
3
Moreover, benzophenone O-vinyloxime (I) at 80 C
decomposes by 13% in 10 h, while in the presence of
DAC (2-methyl-3-butyn-2-ol, dimethylacetylenyl-
carbinol) without BuSH, by only 5%. This result may
be explained by the following DAC-initiated decom-
position pathway:
Also, we observed no intramolecular alkylation of
the benzene ring, which could occur in the presence
of strong acids. The reason may be the above transfer
of the cationic center.
Treatment of oxime I with 2 5 equiv of fluoro-
sulfonic acid in methylene chloride at 60 C gives,
most probably, the corresponding adduct with HF,
benzophenone O-(1-fluoroethyl)oxime (X). This fol-
1
lows from the appearance in the H NMR spectrum
of a quartet signal at 6.51 ppm and a doublet at
Presumably, in the absence of BuSH, the inhibitory
effect of DAC on the decomposition of benzophenone
O-vinyloxime originates from binding of species
which are present in the reaction mixture and catalyze
the decomposition process. The decompostion of
oxime I occurs at a higher rate in the presence of
1
.83 ppm. These signals are similar to those ob-
served in the spectrum of benzophenone O-(1-chloro-
ethyl)oxime (V). The concentration of compound X
in the reaction mixture increased as the temperature
rose to ambient.
LiBF complex with 1,1-dimethoxyethane: under the
4
same conditions (80 C, 10 h) 33% of I is converted
into benzophenone (XI).
The thermal decomposition pattern of pure benzo-
phenone O-vinyloxime (I) depends on the tempera-
ture. At 135 150 C, the reaction was slow, and only
benzophenone (XI) and a tarry material (a broad
It should be noted that even in the presence of such
a strong acid as fluorosulfonic no profound protona-
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 39 No. 10 2003

1
432
ZAITSEV et al.
1
signal at 7.0 8.2 ppm in the H NMR spectrum)
were obtained as nonvolatile products. The formation
of benzophenone was also observed in the photolysis
of benzophenone O-acyloximes [19]. At 195 C,
vigorous decomposition of oxime I occurred, which
resulted in formation of a tarry material containing,
apart from polymeric products, benzophenone and
described above, at 80 C (reaction time 10 h) decom-
position of I occurred to give benzophenone, and
neither oligo- nor poly(benzophenone O-vinyloxime)
was obtained.
Thus the results of the present study showed that
diaryl ketone O-vinyloximes can be involved in some
reactions typical of conventional vinyl ethers, which
are promising from the viewpoint of preparation of
previously inaccessible building blocks for organic
synthesis. Moreover, chemical properties of the
O-vinyloxime moiety in diaryl ketone O-vinyloximes
are more pronounced due to reduced probability for
participation of the aryl groups in condensations and
heterocyclizations. This is interesting from the view-
point of theoretical organic chemistry. The examined
ways of chemical modification of diaryl ketone
O-vinyloximes give new prospects in the purposeful
synthesis of compounds having an N O bond
sequence.
probably benzophenone imine (XII,
Among volatile products, we succeeded in identifying
178.38 ppm).
C
only acetaldehyde (XIII).
Obviously, several thermal decompostion pathways
are possible. At low temperature, the main reaction
pathway is likely to involve intramolecular rearrange-
ment leading to benzophenone, which is characterized
by the least energy of activation among other possible
routes:
EXPERIMENTAL
The H and 13C NMR spectra were recorded on
a Bruker 400DPX spectrometer operating at 400.13
and 101.61 MHz, respectively; chloroform-d was used
as solvent, and HMDS, as internal reference. The IR
spectra were measured on a Bruker ISF-25 instrument.
Initial benzophenone O-vinyloxime (I) was prepared
by the procedure described in [16].
1
Benzophenone O-(1,2-dibromoethyl)oxime (II).
A solution of 0.1 g (0.6 mmol) of bromine in 1 ml of
dry methylene chloride was added with stirring at
room temperature to a solution of 0.13 g (0.6 mmol)
of oxime I in 1 ml of dry methylene chloride. The
solution turned colorless. After 5 min, the solvent
Heating to a higher temperature (195 C) could
induce homolytic dissociation of the N O bond,
which is the most probable site of fragmentation of
ketone O-vinyloximes under electron impact [20]:
was removed under reduced pressure at 40 C. Yield
1
0
.23 g (78%; purity 78%, according to the H NMR
2
0
data), light yellow transparent viscous liquid, n
.6195. IR spectrum (film), cm : 3085 w, 3058 m,
983 m, 2924 w, 2852 w, 1657 m, 1597 m, 1578 w,
492 m, 1445 s, 1420 m, 1367 w, 1341 m, 1327 m,
306 m, 1278 m, 1220 m, 1205 w, 1169 m, 1146 m,
110 s, 1075 m, 1038 w, 1026 m, 986 w, 965 s,
14 s, 871, 850 w, 830 w, 775 s, 696 s, 670 m,
50 m, 606 m, 585 s. H NMR spectrum (CDCl ), ,
= 7.3 Hz), 7.32
.47 m (8H, Harom), 6.65 d.d (1H, -H, J
0.2 Hz, J , = 2.7 Hz), 4.07 t (1H, -H, J ,
1.1 Hz), 3.89 d.d (1H, -H). 13C NMR spectrum
, ppm: 161.97 (C N); 135.27 (anti-C );
132.21 (syn-C ); 130.50 (anti-C ); 129.60 (syn-C );
=
D
1
1
2
1
1
1
9
6
1
3
3
ppm: 7.52 d (2H, anti-o-H, J
7
1
o, m
3
=
=
RH is a molecule having a hydrogen atom.
,
2
1
We also examined the possibility for radical (in
i
(
CDCl3),
the presence of DAC) and cationic (LiBF 1,1-di-
C
4
i
p
p
methoxyethane complex [21]) polymerization of
benzophenone O-vinyloxime (I) in the bulk. As
o
o
m
129.50 (syn-C ); 128.72, 128.43 (anti-C , anti-C );
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 39 No. 10 2003

REACTIVITY OF BENZOPHENONE O-VINYLOXIME
1433
m
p
o
p
1
28.14 (syn-C ); 88.38 (C ); 32.59 (C ). Found, %:
anti-C ); 129.47 (syn-C ); 129.27 (syn-C ); 128.56,
1
o
m
m
28.35 (anti-C , anti-C ); 128.09 (syn-C ); 95.42
CHCl), 24.70 (CH ). Found, %: C 70.59; H 5.51;
N 5.07. C H ClNO. Calculated, %: C 69.36; H 5.43;
N 5.39.
C 48.03; H 3.59; Br 41.58; N 3.66. C H Br NO.
Calculated, %: C 47.03; H 3.42; Br 41.72; N 3.66.
Methyl isopropyl ketone O-(1,2-dibromethyl)-
oxime (IV). Following the above procedure, from
1
5
13
2
(
3
15 14
0
.1 g (0.8 mmol) of compound III and 0.12 g
Benzophenone O-(1-acetoxyethyl)oxime (VI).
A mixture of 0.2 g (0.9 mmol) of oxime I and 0.06 g
(1 mmol) of acetic acid was heated for 0.5 h at 60 C.
The mixture turned light brown. Apart from acetic
acid, the mixture contained mainly benzophenone
O-vinyloxime (I) and benzophenone O-(1-acetoxy-
thyl)oxime (VI) at a ratio of 1:0.1. Heating of the
mixture for an additional 3 h at 80 C increased its
viscosity, the color changed to dark brown, and the
(0.8 mmol) of bromine we obtained 0.2 g of a mixture
consisting of 0.14 g of a light brown mobile liquid,
which contained about 80% (49%) of dibromo
derivative IV, and 0.06 g of a brown tarry material.
Adduct IV was a mixture of E and Z isomers at a ratio
1
of 6:1. IR spectrum (film), , cm : 3041 w, 2970 s,
2
1
1
9
5
6
932 m, 2873 m, 1761 w, 1715 m, 1641 m, 1467 m,
422 m, 1387 w, 1368 m, 1344 m, 1272 w, 1254 w,
237 w, 1215 m, 1184 w, 1147 m, 1112 s, 1024 s,
1
ratio of compounds I and VI became 1:0.7. H NMR
3
86 m, 916 s, 888 m, 839 m, 772 w, 739 w, 669 m,
spectrum (CDCl ), , ppm: 6.60 q (1H, -H, J
=
3
,
1
88 s. H NMR spectrum (CDCl ), , ppm: E isomer:
3
5.5 Hz), 1.44 (3H, -H).
3
.52 d.d (1H, -H, J
= 10.0, J , = 2.7 Hz),
.08 d.d (1H, -H, J , = 11.1 Hz), 3.90 d.d (1H,
H), 2.57 sept (1H, CH, 3J
= 6.8 Hz), 1.12 d
,
Benzophenone O-(1-trifluoroacetoxyethyl)oxime
(VII). A mixture of 0.2 g (0.9 mmol) of oxime I and
0.11 g (1 mmol) of trifluoroacetic acid was heated for
0.5 h at 60 C. The mixture turned dark brown; it con-
2
4
-
HH
3
(
6H, CH ); Z isomer: 6.52 d.d (1H, -H, J
=
=
3
,
2
1
1
0.2 Hz, J , = 2.7 Hz), 4.06 d.d (1H, -H, J
tained about 30% of product VII ( H NMR data).
,
1
1
1.0 Hz), 3.91 d.d (1H, -H), 3.32 sept (1H, CH,
H NMR spectrum (CDCl ), , ppm: 6.76 q (1H, -H,
J , = 5.5 Hz), 1.54 (3H, -H).
3
3
13
3
JHH = 7.0 Hz), 1.06 d (6H, CH ). C NMR spectrum
3
(
(
1
3
CDCl3), C, ppm: E isomer: 168.09 (C N), 88.87
Benzophenone O-(1-methoxyethyl)oxime (VIII).
Trifluoroacetic acid, 0.03 g (0.3 mmol), was added to
a solution of 0.2 g (0.9 mmol) of compound I in 2 ml
of anhydrous methanol, and the mixture was heated
for 15 min under reflux. The solvent was removed
under reduced pressure (50 C) to obtain 0.23 g of
a light yellow viscous liquid which contained 40%
C ), 34.46 (CH), 32.90 (C ), 19.63 [CH(CH ) ],
3 2
2.30 (CH ); Z isomer: 168.09 (C N), 88.87 (C ),
3
2.83 (C ), 27.58 (CH), 19.05 [CH(CH ) ], 15.54
3
2
(CH ). IR spectrum of the tarry material (film),
,
3
1
cm : 3351 s, br, 3141 s, br, 2975 w, 2936 w, 2875 w,
2
1
751 s, br, 1688 m, 1467 m, 1423 w, 1371 m,
092 m, 1060 m, 980 w, 939 w, 893 w, 777 w, 596 w.
Benzophenone O-(1-chloroethyl)oxime (V). Dry
1
1
of product VIII ( H NMR data). H NMR spectrum
3
(
CDCl ), , ppm: 5.26 q (1H, -H, J
= 5.4 Hz),
3
,
1
.39 (3H, -H).
hydrogen chloride prepared by reaction of sodium
chloride with sulfuric acid was passed over a period
of 10 min through a solution of 0.3 g (1.3 mmol) of
oxime I in 3 ml of dry methylene chloride. The sol-
vent was distilled off under reduced pressure at 40 C.
Yield 0.35 g (87%; purity 87%, according to the H
NMR data), light yellow transparent viscous liquid,
n
3
2
1
1
1
8
5
Benzophenone O-(2-trifluoroacetylvinyl)oxime
(IX). A solution of 1.41 g (6.7 mmol) of trifluoro-
acetic anhydride in 1.5 ml of dry diethyl ether was
added over a period of 3 min under stirring to a solu-
tion of 0.5 g (2.2 mmol) of compound I and 0.21 g
1
(
2.7 mmol) of pyridine in 1.5 ml of dry diethyl ether.
The mixture was stirred for 2.5 h, kept for 12 h at
0 C, and poured under stirring into 40 ml of hexane
2
0
1
= 1.5880. IR spectrum (film), , cm : 3083 w,
D
060 m, 3027 w, 2998 w, 2989 w, 2967 w, 2931 m,
854 w, 1958 w, 1890 w, 1811 w, 1762 w, 1660 w,
614 w, 1594 w, 1569 w, 1494 m, 1445 s, 1381 m,
329 m, 1305 m, 1265 m, 1169 m, 1136 s, 1113 s,
076 w, 1020 m, 1001 w, 980 m, 943 s, 922 w,
2
cooled to 0 C. The precipitate was filtered off, and
the filtrate was evaporated under reduced pressure
(
40 C) to obtain 0.87 g of a light red brown trans-
parent liquid which contained about 25% of product
IX. Yield 31%. H NMR spectrum (CDCl ), , ppm:
8.30 d (1H, -H, J = 12.4 Hz), 6.27 d (1H, -H).
1
69 m, 774 s, 737 w, 696 s, 668 m, 652 m, 629 m,
3
1
3
99 m, 540 w, 492 m. H NMR spectrum (CDCl ),
3
,
3
,
ppm: 7.50 d (2H, anti-o-H, J
.43 m (8H, Harom), 6.40 q (1H, -H, J = 5.8 Hz),
.78 d (3H, -H). C NMR spectrum (CDCl ),
= 8 Hz), 7.30
o, m
Reaction of benzophenone O-vinyloxime (I) with
fluorosulfonic acid. A mixture of 0.07 g (0.7 mmol)
of fluorosulfonic acid and CD Cl was placed in
3
7
1
,
1
3
,
C
3
2
2
i
i
ppm: 160.59 (C N); 132.68 (anti-C ); 130.12 (syn-C ;
a 5-mm NMR ampule and cooled to 70 C, and
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 39 No. 10 2003

1
434
ZAITSEV et al.
a solution of 0.03 g (0.13 mmol) of compound I in
Cationic polymerization of benzophenone
O-vinyloxime (I). The procedure was the same as
CD Cl was added. The ampule was mounted into
2
2
the probe of NMR spectrometer, maintained at 70 C,
and the H NMR spectra were recorded each time as
above, but a solution of 0.003 g (2%) of LiBF in
0.05 ml of 1,2-dimethoxyethane was added. The ratio
4
1
the temperature rose by 5 C. At 60 C, new signal
appeared, , ppm: 6.51 q and 1.83 d ( J , = 5.6 Hz),
of compounds I and XI was 2:1.
3
In the above experiments, the contents of the
ampule turned brown and became more viscous. After
cooling and opening of the ampules, no evoluton of
gaseous products was observed, and the initial weight
of the material remained unchanged. The resulting
materials were readily soluble in most organic sol-
vents, such as acetone, benzene, petroleum ether, and
isooctane.
which were assigned to benzophenone O-(1-fluoro-
ethyl)oxime (X). The intensity of these signals in-
creased as the temperature rose to 20 C, while the
signals from compound I decreased in intensity.
However, even after 20 h at room temperature, only
a half of I was converted into product X.
Decomposition of benzophenone O-vinyloxime
(
I) on slow heating. A glass ampule was charged
When analogous experiments were carried out
under more severe conditions (110 C, 12 h), complete
decomposition of substrate I occurred. The major
products were benzophenone (XI) and polymeric
compounds which were characterized by very broad
with 0.1 g of oxime I and was heated on an oil bath
at a rate of 5 deg/min. When the temperature reached
1
35 C, quiet decomposition of the substrate began,
and it turned dark. The ampule was continued to heat
up to 150 C and was then cooled. According to the
NMR spectra, the main components of the resulting
1
signals in the H NMR spectra in the range from
6
.9 to 8.1 ppm. No upfield signals from the expected
1
3
material were benzophenone (XI) [ C NMR spectrum
oligomers or polymers were observed. The resulting
materials were readily soluble in most organic sol-
vents (acetone, benzene, diethyl ether, petroleum
ether, isooctane, and methanol) and insoluble in water.
i
(
(
CDCl ), , ppm: 196.76 (C O), 137.66 (C ), 132.44
3 C
p
o
m
C ), 130.09 (C ), 128.33 (C )] and polymeric prod-
1
ucts which showed in the H NMR spectra broad
signals in the range from 6.9 to 8.1 ppm.
Decomposition of benzophenone O-vinyloxime
I) on fast heating. A receiver equipped with a drop-
REFERENCES
(
ping funnel was heated to 195 C, and a small amount
of oxime I was added dropwise. The substrate boiled
up 1 s after it contacted with the hot surface. The
evolved gaseous products were passed through CDCl3
cooled to 70 C. When the entire amount of oxime
1. Favorskii, A.E., Izv. Akad. Nauk SSSR, Otd. Khim.
Nauk, 1940, no. 2, p. 181.
2
.
Trofimov, B.A., Geteroatomnye proizvodnye atseti-
lena. Novye polifunktsional’nye monomery, reagenty
i poluprodukty (Heteroatom Acetylene Derivatives.
New Polyfunctional Monomers, Reagents, and Inter-
mediate Products), Moscow: Nauka, 1981.
I was added, the heating bath was removed. The
1
H NMR spectrum of the resulting black tarry material
contained signals belonging to compounds I and XI
and broad signals in the range from 6.5 to 8.2 ppm.
In the 13C NMR spectrum, apart from the signals of
3
4
.
.
Trofimov, B.A. Curr. Org. Chem., 2002, vol. 6,
p. 1121.
Mikhaleva, A.I. and Gusarova, N.K., Atsetilen: reak-
tsii i proizvodnye. Bibliografiya nauchnykh trudov
B.A. Trofimova (Acetylene and Its Derivatives.
Bibliography of Scientific Works of B.A. Trofimov),
Novosibirsk: Izd. Sib. Otd. Ross. Akad. Nauk, 1999;
Trofimov, B.A. and Nedolya, N.A., Rev. Heteroatom
Chem., 1993, vol. 9, p. 205.
I and XI, a signal from a quaternary carbon atom was
1
present at
178.38 ppm. In the H NMR spectrum
C
of the gaseous decomposition products we identified
signals belonging to acetaldehyde, , ppm: 9.80 q
3
(
1H, CHO, J
HH
= 2.9 Hz), 2.20 d (3H, CH3).
Thermal polymerization of benzophenone
O-vinyloxime (I). A 2-ml ampule was charged with
.35 g (1.6 mmol) of compound I. The ampule was
purged with argon, sealed, and heated for 10 h at
5
.
Sinegovskaya, L.M. and Trofimov, B.A., Usp. Khim.,
0
1
996, vol. 65, no. 12, p. 1091; Trofimov, B.A.,
Z. Chem., 1986, vol. 26, no. 2, p. 41; Sinegov-
skaya, L.M., Keiko, V.V., and Trofimov, B.A., Sulfur
Rep., 1987, vol. 7, no. 5, p. 337; Nedolya, N.A. and
Trofimov, B.A., Sulfur Rep., 1994, vol. 15, no. 2,
p. 237; Nedolya, N.A. and Trofimov, B.A., Sulfur
Rep., 1994, vol. 15, no. 3, p. 339; Nedolya, N.A.,
Trofimov, B.A., and Senning, A., Sulfur Rep., 1996,
vol. 17, no. 2, p. 183.
1
8
0 C. The resulting material was analyzed by H
NMR spectroscopy. The ratio of compounds I and XI
was 7:1.
Radical polymerization of benzophenone
O-vinyloxime (I). The procedure was the same as
above, but 0.007 g (3%) of DAC was added. The ratio
of compounds I and XI was 21:1.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 39 No. 10 2003

REACTIVITY OF BENZOPHENONE O-VINYLOXIME
1435
6
7
.
.
Khimicheskaya entsiklopediya (Chemical Encyclo-
pedia), Moscow: Bol’shaya Rossiiskaya Entsiklo-
pediya, 1992, vol. 3, p. 1226.
13. Trofimov, B.A., Korostova, S.E., Mikhaleva, A.I.,
Sobenina, L.N., Vasil’ev, A.N., and Nesterenko, R.N.,
Khim. Geterotsikl. Soedin., 1983, no. 2, p. 273.
1
4. Advances in Heterocyclic Chemistry, Katritzky, A.R.,
Trofimov, B.A., Mikhaleva, A.I., Vasil’tsov, A.M.,
Schmidt, E.Yu., Tarasova, O.A., Morozova, L.V.,
Sobenina, L.N., Preiss, T., and Henkelmann, J.,
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Ed., San Diego: Academic, 1990, vol. 51, p. 177.
15. Korostova, S.E., Shevchenko, S.G., and Siga-
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1
6. Zaitsev, A.B., Vasil’tsov, A.M., Schmidt, E.Yu.,
Mikhaleva, A.I., Morozova, L.V., Afonin, A.V.,
Ushakov, I.A., and Trofimov, B.A., Tetrahedron,
8
9
.
.
Trofimov, B.A., Schmidt, E.Yu., Mikhaleva, A.I.,
Vasil’tsov, A.M., and Afonin, A.V., Mendeleev
Commun., 2000, no. 1, p. 29.
2
002, vol. 58, p. 10043.
Trofimov, B.A., Schmidt, E.Yu., Vasil’tsov, A.M.,
Mikhaleva, A.I., Zaitsev, A.B., Morozova, L.V.,
Gorshkov, A.G., Arndt, J.-D., and Henkelmann, J.,
Synthesis, 2001, no. 16, p. 2427.
1
1
1
7. Shostakovskii, M.F., Prostye vinilovye efiry (Vinyl
Ethers), Moscow: Akad. Nauk SSSR, 1952.
8. Hojo, M., Masuda, R., and Okada, E., Synthesis,
1
990, no. 4, p. 347.
1
1
0. Trofimov, B.A., Schmidt, E.Yu., Mikhaleva, A.I.,
Vasil’tsov, A.M., Larina, L.I., and Klyba, L.V.,
Mendeleev Commun., 1999, no. 6, p. 238.
9. Lalevee, J., Allonas, X., Fouassier, J.P., Tachi, H.,
Izumitani, A., Shirai, M., and Tsunooka, M.,
J. Photochem. Photobiol. A, 2002, vol. 151, p. 27.
1. Vasil’tsov, A.M., Shmidt, E.Yu., Mikhaleva, A.I.,
Zaitsev, A.B., Tarasova, O.A., Afonin, A.V.,
Toryashinova, D.-S.D., Il’icheva, L.N., and Trofi-
mov, B.A., Russ. J. Org. Chem., 2001, vol. 37,
p. 334.
2
2
0. Yurovskaya, M.A., Druzhinina, V.V., Tyurekhodzha-
eva, M.A., and Bundel’, Yu.G., Khim. Geterotsikl.
Soedin., 1984, no. 1, p. 69.
1. Trofimov, B.A., Morozova, L.V., Tatarinova, I.V.,
Khil’ko, M.Ya., Ivanova, N.I., Mikhaleva, A.I., and
Scotheim, T., Vysokomol. Soedin., Ser. B, 2002,
vol. 44, no. 11, p. 2048.
1
2. Trofimov, B.A. and Mikhaleva, A.I., N-Vinilpirroly
(
N-Vinylpyrroles), Novosibirsk: Nauka, 1984.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 39 No. 10 2003