Reaction of 2,3-dihalopropionic acids and their derivatives with P- and N-nucleophiles

Article abstract of DOI:10.1007/s11176-006-0009-z

3-(Triphenylphosphoniochlorido)acrylic and 2,3-dichloropropionic acids react with triphenylphosphine to form 1,2-bis(triphenylphosphoniochlorido) ethane. Under analogous conditions, 2,3-dibromopropionic acid undergoes debromination followed by triphenylphosphine addition to give, after water treatment, 3-(triphenylphosphoniobromido)propionic acid. 2,3- Dihalopropionitriles react similarly, providing 3-(triphenylphosphoniohalido) propionitriles. The reaction of 2,3-dibromopropionamide with triphenylphosphine was performed to show that E-(triphenylphosphoniobromido)acrylic acid is capable, by contrast to what was reported previously, of reacting with triphenylphosphine. Pyridine forms with 2,3-dihalopropionic acids vinylpyridinium halides, while the reactions with aliphatic amines gives rise to dehydrohalogenation products.

Full text of DOI:10.1007/s11176-006-0009-z

Russian Journal of General Chemistry, Vol. 75, No. 12, 2005, pp. 1889 1894. Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 12, 2005,
pp. 1978 1983.
Original Russian Text Copyright
2005 by Khachikyan, Tovmasyan, Indzhikyan.
Reaction of 2,3-Dihalopropionic Acids and Their Derivatives
with P- and N-Nucleophiles
R. Dzh. Khachikyan, N. V. Tovmasyan, and M. G. Indzhikyan
Institute of Organic Chemistry, National Academy of Sciences of Armenia, Erevan, Armenia
Received January 19, 2005
Abstract 3-(Triphenylphosphoniochlorido)acrylic and 2,3-dichloropropionic acids react with triphenyl-
phosphine to form 1,2-bis(triphenylphosphoniochlorido)ethane. Under analogous conditions, 2,3-dibromopro-
pionic acid undergoes debromination followed by triphenylphosphine addition to give, after water treatment,
3
-(triphenylphosphoniobromido)propionic acid. 2,3-Dihalopropionitriles react similarly, providing 3-(triphenyl-
phosphoniohalido)propionitriles. The reaction of 2,3-dibromopropionamide with triphenylphosphine was
performed to show that E-(triphenylphosphoniobromido)acrylic acid is capable, by contrast to what was
reported previously, of reacting with triphenylphosphine. Pyridine forms with 2,3-dihalopropionic acids vinyl-
pyridinium halides, while the reactions with aliphatic amines gives rise to dehydrohalogenation products.
Regardless of the fact that the reactions of halo-
acrylic and dihalopropionic acids with nucleophiles
have been studied in sufficient detail, the information
on the corresponding reactions involving P(III)
compounds is scarce.
48%, and at room temperature it was 44%. The reac-
tion was suggested to involve dehydrochlorination of
dichloropropinic acid to -chloroacrylic, addition of
triphenylphosphine, neutralization of the resulting
betaine, rehydrochlorination, and addition of a further
triphenylphosphine molecule with the attendant de-
carboxylation.
Pattenden and Walker [1] found that -haloacrylic
acids smoothly react with triphenylphosphine in
benzene at 0 25 C to form phosphonium salts con-
taining a 2-carboxyvinyl group and, which deserves
special mentioning, the reactions products are always
E isomers, irrespective of the configuration of the
starting halide. The reaction of triphenylphosphine
with -bromoacrylic acid resulted in the isolation of
Evidence for the suggested reaction scheme was
obtained by the preparation of 1,2-bis(triphenylphos-
phoniochlorido)ethane in a yield of 58% by the reac-
tion of triphenylphosphine hydrochloride with (E)-3-
(triphenylphosphoniochlorido)acrylic acid under the
same conditions. Analogously, from (E)-3-(triphenyl-
phosphoniobromido)acrylic acid and triphenylphos-
phine hydrobromide under the conditions in [1] we
obtained 1,2-bis(triphenylphosphoniobromido)ethane.
Our results contradict the statement of Pattenden and
Walker [1] that (E)-3-( triphenylphosphoniobromido)-
acrylic acid is inert toward triphenylphoshine hydro-
bromide.
1,2-bis(triphenylphosphoniobromido)ethane,
along
with the E-monosalt. The referees stated that the two
products form independently of each other, since the
salt is incapable of reacting with triphenylphosphine
and its hydrobromide under the reaction conditions
[1].
We previously studied the reaction of triphenyl-
phosphine with -chloroacrylic acid and found that it
yields (E)-3-(triphenylphosphoniochlorido)acrylic
acid [2].
To provide further evidence for the suggested
scheme, we reacted 2,3-dichloropropionic acid with
triphenylphosphine in benzene. The use of benzene
1
instead of acetonitrile enabled us to detect in the H
In the present work we focused on the reactions of
triphenylphosphine with a precursor of -chloroacrylic
acid, viz. 2,3-dichloropropionic acid, as well as with
and 31P NMR spectra intermediate reaction products,
-chloroacrylic and (E)-3-(triphenylphosphoniochlo-
ride)acrylic acids, along with the bis-salt. The first
product was detected in the experiment at room
temperature, and the second at 50 C (reagent ratio
2
,3-dibromopropionic acid, and derivatives of the two
acids. It was found that 2,3-dichloropropionic acid
reacts with triphenylphosphine in acetonitirile at a 1:2
reagent ratio at 50 C to form 1,2-bis(triphenylphos-
phoniochlorido)ethane in ~68% yield. The yield of
the same product at a 1:1 reagent ratio at 50 C was
1
:2).
As would be expected, quite a different pattern was
observed in going from dichloropropionic acid to its
1
070-3632/05/7512-1889 2005 Pleiades Publishing, Inc.

1890
KHACHIKYAN et al.
(
C H ) P
6 5 3
CH CH COOH
CH =C COOH
2
2
(
C H ) P HCl
6 5 3
Cl Cl
Cl
(
C H ) P
6 5 3
+
+
(
C H ) P CH C COOH
(C H ) P CH CH COO
6
5 3
2
6
5 3
2
Cl
Cl
(
C H ) P
6 5 3
HCl
+
(
C H ) P CH CHCl COOH
6 5 3 2
(
C H ) P HCl
6 5 3
Cl
(
C H ) P HCl
6 5 3
+
+
+
(
C H ) P CH=CHCOOH
(C H ) P CH CH P (C H )
6
5 3
6
5 3
2
2
6
5 3
CO2
Cl
Cl
Cl
bromine-containing analog. It is well known that
phosphines, including triphenylphosphine, are highly
bromophilic and readily spit off a bromine molecule
from vicinal dihalides. The presence of the electron
acceptor carboxy group in 2,3-dibromopropionic acid,
too, favors this reaction. In this connection the ex-
clusive formation of 3-(triphenylphosphoniobromido)-
propionic acid and triphenylphosphine oxide in the
reaction of 2,3-dibromopropionic acid and triphenyl-
phosphine followed by hydrolysis becomes under-
standable. The yields of these products after refluxing
the reagents in acetonitrile at an acid-to-phosphine
ratio of 1:2 were 73%. The same results were ob-
tained when the reaction was performed at 50 C and
room temperature, as well as in methanol or benzene
instead of acetonitrile. At a 1:1 reagent ratio, unreacted
acid was isolated as acomplex with the triphenylphos-
phine oxide formed. Addition of triphenylphospine to
the complex gave 3-(triphenylphosphoniobromido)-
propionic acid. The reaction probably occurs by the
following scheme.
O
(
C H ) P
(C H ) P
6 5 3
6
5 3
+
CH CH COOH
CH =CH COOH
(C H ) P CH CHC
6 5 3 2
2
2
(
C H ) PBr
2
OH
6
5 3
Br Br
O
O
O
O
(
C H ) PBr
+
6
5 3
2
(C H ) P CH CH C
+
+
6
5 3
2
2
(
C H ) P CH CH C
(C H ) P CH CH C
6
5 3
2
2
6
5 3
2
2
(C H ) P=O
6 5 3
6 5 3
Br
+
Br
Br
O P (C H )
Br
O
H O
+
2
(
C H ) P CH CH C
6
5 3
2
2
HBr
Br
OH
Note that the reaction of triphenylphosphine with
,3-dichloropropionic acid at 50 C in benzene, too,
ratio gave as little as 11% of 3-(triphenylphosphonio-
bromido)propionitrile and 66% of triphenylphosphine
oxide. By IR spectroscopy we detected in the aqueous
solution acrylonitrile formed by debromination.
2
gave 3-(triphenylphosphoniochlorido)propionic acid
along with a bis-salt and an , -unsaturated salt in
roughly equal yields. The first salt might form in no
other way than via dehydrochlorination of dichloro-
propionic acid to acrylic under the action of triphenyl-
phosphine. The resulting data point to a considerable
solvent effect on the reaction pathway.
With the dichloro analog, too, dehalogenation was
a single reaction pathway. The yield of 3-(triphenyl-
phosphoniochlorido)propionitrile at a 1:2 reagent
ratio was 50%. Triphenylphosphine oxide was isolated
in the same yield after hydrolysys. The resulting data
seem unexpected when compared with those obtained
with structurally related acids; however, they are
consistent with the high halophilicity of phosphines.
The introduction of such an electron-acceptor group as
C N appears to allow the chlorine atom to be split
off as a cation.
2
,3-Dibromopropionitrile behaves similarly to 2,3-
dibromopropionic acid. The refluxing of the former in
mol of triphenylphosphine provides 3-(triphenyl-
2
phosphoniobromido)propionitrile (yield 53%). After
hydrolysis, triphenylphosphine oxide was isolated in
the same yield. The same reaction at a 1:1 reagent
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 75 No. 12 2005

REACTION OF 2,3-DIHALOPROPIONIC ACIDS AND THEIR DERIVATIVES
1891
CH CH CN + (C H ) P
CH =CH CN + (C H ) PX ,
2
6
5 3
2
6
5 3
2
X
X
(
C H ) PX
6 5 3 2
+
(C6H5)3P+ CH2CH2 CN,
X
CH =CH CN + (C H ) P
(C H ) P CH CH CN
2
6
5 3
6
5 3
2
H O
2
X = Cl, Br.
Tung and Speziale [3] have studied the reaction of
triphenylphosphine with 2,3-dibromopropionamide in
in dioxane at 20 25 C at a 1:2 reagent ratio, yielding
an ylide, and proposed the following reaction scheme.
+
Br
BrCH CH C NH
Br P (C H )
6
5 3
(
C H ) P
6 5 3
CH CH C NH
BrCH CH C NH2
2
2
2
2
2
<
Br Br O
O
O
(C H ) P
6
5 3
P(C H )
6
5 3
(
C H ) P
6 5 3
BrCH C C NH2
2
O
We reproduced in detail the experiment in [3] to
obtain 3-(triphenylphosphoniobromido)propioamide
in 80% yield. The structure of the product was estab-
lished by H NMR.
1
Br
(
C H ) P
6 5 3
CH CH C NH
CH =CH C NH + (C H ) P Br
2
2
2
2
6
5 3
2
Br Br O
O
(
C H ) P
(C6H5)3P Br2
6
5 3
+
+
(
C H ) P CH CH C NH
(C6H5)3P CH2CH2 C NH2
6
5 3
2
2
H O
2
Br
O
O
Thus, as would be expected, dibromopropionic acid
and its nitrile and amide react with triphenylphosphine
halido)methacrylic acids. The reaction occurs in a
sterespecific fashion: The Z-halide gives a Z isomer,
by a common scheme whose first act is debromination. while the E-halide gives an E isomer. The resulting
data suggest a tetrahedral reaction mechanism [2].
To compare the behavior of dihalopropionic acids
and their nitriles toward triphenylphosphine and
tertiary amines, we reacted them with aliphatic tertiary
amines and pyridine. The information on reactions of
haloacrylic and dihalopropionic acids with tertiary
amines has been almost lacking from the literature.
Recently we found that pyridine reacts with -chloro-
and -bromomrthacrylic acids to form 3-(pyridinio-
In the present work we found that 2,3-dichloropro-
pionic acid smoothly reacts with trimethyl-, triethyl-,
dimethylallyl-, and diethylallylamines in acetonitrile
under reflux to afford dehydrochlorination products,
viz. -chloroacrylic acid and amine hydrochlorides, in
nearly quantitative yields. 2,3-Dibromopropionic acid
behaves similarly.
R N + CH X CH X COOH
R N HX + CH =CX COOH,
3 2
3
2
2
R N = (CH ) N (I), (C H )N (II, V), (CH ) N CH CH=CH (III), (C H ) N CH CH=C(CH ) (IV, VI); X = Cl (I IV),
3
3 3
2
5
3 2
2
2
2
5 2
2
3 2
Br (V, VI).
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 75 No. 12 2005

1892
KHACHIKYAN et al.
Quite a different pattern is observed with pyridine.
Its reaction with dihalopropionic acids results in
exclusive formation of vinylpyridinium salts in high
yields. The reactions presumably involve nucleophilic
substitution, decarboxylation, and chloride anion
formation.
O
+
CH X CHX C
O
2
+
OH
N CH C
X
N
O H
Hb
CH X
2
+
N C==C
CO2, HX
X
a
H Hc
X = Cl, Br.
The reaction of dihalopropionic acids with pyridine
can be used as a good alternative to existing
methods of synthesis of vinylpyridinium salts.
b. A mixture of 0.737 g of (E)-3-(triphenylphos-
phoniochlorido)acrylic acid, 0.524 g of triphenylphos-
phine, and 0.278 g of HCl in acetonitrile was heated
for 20 h at 50 C. The reaction mixture was treated as
described above. The melting points, elemental
analyses, and H and P NMR spectra are identical
to those of the sample obtained by procedure a.
We found that nitriles of the above dihalopropionic
acids react with tertiary amines, including pyridine, to
form dehydrohalogenation products exclusively. The
yields of amines are almost quantitative. -Halonit-
riles could not be isolated because of tarring.
1
31
Reaction of 2,3-dichloropropionic acid with tri-
phenylphosphine in benzene. A mixture of 0.715 g
of 2,3-dichloropropionic acid and 2.62 g of triphenyl-
phosphine in benzene was heated for 20 h at 50 C.
The benzene the from the oily precipitate, and the
latter was treated with a mixture of chloroform and
ether to obtain 1.8 g of a mixture of (E)-3-(triphenyl-
phosphoniochlorido)acrylic, 3-(triphenylphosphonio-
chlorido)propionic acid, and 1,2-bis(triphenylphos-
phoniochlorido)ethane an a roughly 1:1:1 ratio (by
R N + CH X CHX CN
3
2
R N HX + [CH =CX CN],
3
2
X = Cl, Br.
Thus, we developed an effective synthetic approach
to -chloroacrylic acids through the reaction of 2,3-
dichloropropionic acid with triethylamine.
1
1
H NMR). H NMR spectrum of (E)-3-(triphenyl-
phosphoniochlorido)acrylic acid (DMSO-d ), , ppm.:
6
EXPERIMENTAL
+
6
.8 d.d (1H, P C=C H , J 21.2, J 16.8 Hz),
cis PH HH
+
1
7.6 8.0 m (15H, C H ), 8.3 d.d (1H, P HC=, J 20.4,
6 5 PH
The H NMR spectra were measured on a Varian
31
JHH 16.8 Hz), 12.5 br (1H, COOH). P NMR spec-
trum:
Mercury-300 spectrometer at 300 MHz, internal
reference TMS.
1
24.80 ppm. H NMR spectrum of 3-(triphe-
P
nylphosphoniochlorido)propionic acid (DMSO-d ), ,
6
1
,2-Bis(triphenylphosphoniochlorido)ethane.
ppm: 2.7 m (2H, CH COOH, J 11.8, 7.7 Hz), 3.9 m
2
a. A mixture of 0.715 g of 2,3-dichloropropionic acid
and 2.62 g of triphenylphosphine was heated in aceto-
nitrile for 20 h at 50 C. The reaction mixture was
poured into ether, the white crystals that formed were
filtered off, treated with water, extracted with chloro-
(2H, PCH , J 13.6, 7.7 Hz), 7.6 8.0 m (15H, C H ),
2
6
5
3
1
12.5 br (1H, COOH).
P NMR spectrum:
P
1
31
30.20 ppm. The H and P NMR spectra of 1,2-bis-
(triphenylphosphoniochlorido)ethane are identical to
those given above.
form, and reprecipitated with ether to obtain 2.1 g
1
(
(
68%) of the product, mp >265 C. H NMR spectrum
Reaction of 2,3-dibromopropionic acid with tri-
phenylphosphine. a. Reagent ratio 1:2. A mixture of
1.16 g of 2,3-dibromopropionic acid and 2.62 g of tri-
phenylphosphine in acetonitrile was heated under
reflux for 9 h and then poured into water. Triphenyl-
phosphine, 1.01 g (73%), precipitated and was filtered
off, mp 154 C. The filtrate was extracted with chlo-
DMSO-d CCl , 1:3), , ppm.: 4.31 br.d (4H,
6
4
+
P CH , J 4.5 Hz), 7.70 br.t (12H, C H , J 7.8 Hz),
2
6
5
7
.86 br.t (1H, C H , J 7.4 Hz), 7.91 7.99 m (12H,
6 5
3
1
C H ). P NMR spectrum: 31.60 ppm. Found, %:
6
5
P
C 73.24; H 5.5; Cl 11.42; P 9.98. C H Cl P . Cal-
3
8
34
2 2
culated, %: C 73.19; H 5.46; Cl 11.39; P 9.95.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 75 No. 12 2005

REACTION OF 2,3-DIHALOPROPIONIC ACIDS AND THEIR DERIVATIVES
1893
roform. 3-(Triphenylphosphoniobromido)propionic
acid, 1.45 g (73%), was precipitated from the chloro-
form layer with ether, mp 186 C. H NMR spectrum
phosphine in dioxane was added dropwise over the
course of 1 h to a solution of 1.16 g of 2,3-dibromo-
propionamide in dioxane. The reaction mixture was
stirred for 3 h at 20 25 C. The crystals that formed
were filtered off and washed with dioxane. Hydrolysis
gave 1.65 g (80%) of 3-(triphenylphosphoniobromido)-
1
(
DMSO-d CCl , 1:1), , ppm: 2.62 m (2H,
6 4
CH COOH, J 11.7, 7.7 Hz), 3.87 m (2H, CH P, J
2
2
1
3.5, 7.7 Hz), 7.72 7.78 m (6H, C H ), 7.82-7.91 m
6 5
3
1
1
(9H, C H ), 12.5 br (1H, COOH). P NMR spectrum:
6 5
propionamide, mp 200 C. H NMR spectrum
3
0.16 ppm. Found, %: C 60.84; H 4.90; Br 19.41;
P
(DMSO-d CCl , 1:3), , ppm.: 2.58 m (2H,
6
4
P 7.61. C H BrO P. Calculated, %: C 60.72; H 4.82;
2
1
20
2
CH CONH , J 11.7, 7.7 Hz), 3.8 m (2H, PCH ,
2 2 2
Br 19.28; P 7.47.
J 13.5, 7.7 Hz), 7.65 7.8 m (6H, C H ), 7.82 7.88 m
6
5
3
1
The same results were obtained with the reaction
performed at 50 C and room temperature, as well as
in methanol or benzene instead of acetonitrile.
(9H, C H ). P NMR spectrum:
30.66 ppm.
6
5
P
Found, %: C 60.92; H 5.14; Br 19.42; N 3.41; P 7.52.
C H BrONP. Calculated, %: C 60.87; H 5.07; Br
2
1
21
1
9.32; N 3.38; P 7.49.
b. Reagent ratio 1:1. A mixture of 1.16 g of 2,3-
dibromopropionic acid and 1.31 g of triphenylphos-
phine in acetonitrile was heated under reflux for 9 h,
poured into water, and filtered to separate 1.3 g (44%)
of a complex of unreacted acid with the triphenylphos-
phine oxide formed, mp 90 C. The aqueous layer was
extracted with chloroform. 3-(Triphenylphosphonio-
bromido)propionic acid, 0.56 g (56%), was precipi-
tated from the chloroform layer with ether, mp 186 C.
Reactions of 2,3-dihalopropionic acids and their
nitriles with aliphatic tertiary amines. A mixture of
.007 mol of 2,3-dihalopropionic acid or 2,3-dihalo-
0
nitrile, 0.007 mol of tertiary amine, and 8 10 ml of
acetonitrile was heated under reflux for 2 3 h and
then poured into ether. Tertiary amine hydrohalides
precipitated and were filtered off and washed with
ether. Yields 93 99%. Given are comp. no. and mp,
C: I 271, II 251, III 117, IV 163, V 243, and VI 138.
1
31
The H and P NMR spectra are consistent with those
of the sample obtained by procedure a. Found, %: C
6
0.84; H 4.90; Br 19.41; P 7.61. C H BrO P. Cal-
21 20 2
N-Vinylpyridinium halides. A mixture of 1 g of
,3-dichloropropionic acid and 0.55 g of pyridine in
acetonitrile was heated under reflux for 8 h. The pre-
cipitate that formed was filtered off, washed with
culated, %: C 60.72; H 4.82; Br 19.28; P 7.47.
2
Reactions of 2,3-dihalopropionitriles with tri-
phenylphosphine were performed by the above
procedures. The reaction of 0.005 mol of 2,3-dibro-
mopropionitrile and 0.01 mol of triphenylphosphine
in acetonitrile and subsequent hydrolysis gave 0.74
g (53%) of triphenylphosphine oxide, mp 154 C, and
acetonitrile, and dried in a vacuum to obtain 0.94 g
1
(
95%) of N-vinylpyridinium chloride, mp 175 C. H
NMR spectrum (DMSO-d CCl , 1:3), , ppm.:
6
4
a
5
.14 d.d (1H, H , =CH, J 13.1, 9.0 Hz), 5.2 d.d (1H,
H , =CH , J 9.0, 4.6 Hz), 5.50 d.d (1H, H , =CH ,
J 13.1, 4.6 Hz), 8.24 d.d (2H, H , J 7.8, 6.4 Hz),
.74 t.t (1H, H , J 7.8, 1.2 Hz), 9.38 d.d (2H, H , J
1.05 g (53%) of 3-(triphenylphosphoniobromido)pro-
b
c
1
2
2
pionitrile, mp 210 C. H NMR spectrum (DMSO-d6
CCl , 1:3), , ppm: 2.63 m (2H, CH CN, J 11.7,
7
2
4
2
3
1
8
6
.7 Hz), 3.8 m (2H, CH P, J 13.5, 7.7 Hz), 7.74
2
.4, 1.1 Hz). Found, %: C 59.50; H 5.77; Cl 25.51;
7
.78 m (6H, C H ), 7.84 7.93 m (9H, C H ). Found,
6
5
6
5
N 9.91. C H ClN. Calculated, %: C 59.36; H 5.65;
%
: C 63.75; H 4.82; Br 20.42; N 3.62; P 7.92.
7
8
Cl 25.09; N 9.89. N-Vinylpyridinium bromide was
obtained in a similar way from 1.16 g of 2,3-dibro-
C H BrNP. Calculated, %: C 63.64; H 4.79; Br
2
1
19
2
0.20; N 3.54; P 7.82.
mopropionic acid and 0.4 g of pyridine. Yield 0.92 g
With the chlorine analog, 0.7 g (50%) of triphenyl-
1
(
99%), mp 145 C. H NMR spectrum (DMSO-d
6
phosphine oxide, mp 154 C, and 0.89 g (50%) of 3-
triphenylphosphoniochlorido)propionitrile, mp 230 C,
a
CCl , 1:3), , ppm: 5.14 d.d (1H, H , =CH, J 13.1,
9.0 Hz), 5.22 d.d (1H, H , =CH , J 9.0, 4.6 Hz),
.50 d.d (1H, H , =CH , J 13.1, 4.6 Hz), 8.24 d.d (2H,
H , J 7.8, 6.4 Hz), 8.74 t.t (1H, H , J 7.8, 1.2 Hz),
4
(
b
1
2
were obtained. H NMR spectrum (DMSO-d CCl ,
6
4
c
5
2
1
4
:3), , ppm.: 2.84 m (2H, CH CN, J 11.7, 7.7 Hz),
2
2
3
.4 m (2H, PCH , J 13.5, 7.7 Hz), 7.6 7.8 m (6H,
2
1
9
.38 d.d (2H, H , J 6.4, 1.1 Hz). Found, %: C 45.34;
C H ), 7.82 8.0 m (9H, C H ). Found, %: C 71.71;
6
5
6
5
H 4.47; Br 43.35; N 7.67. C H BrN. Calculated, %:
H 5.48; Cl 10.05; N 3.91; P 8.92. C H ClNP. Cal-
culated, %: C 71.69; H 5.41; Cl 10.01; N 3.98;
P 8.82.
7
8
2
1
19
C 45.16; H 4.30; Br 43.01; N 7.53.
Reaction of 2,3-dihalonitriles with pyridine. A
mixture of 0.005 mol of dihalonitrile and 0.005 mol
of pyridine in acetonitrile was heated under reflux for
Reaction of 2,3-dibromopropionamide with tri-
phenylphosphine. A solution of 2.62 g of triphenyl-
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 75 No. 12 2005

1894
KHACHIKYAN et al.
8
h. Yields of hydrohalides, %: 85 (X = Cl) and 81
REFERENCES
(X = Br); mp 82 and 200 C, respectively.
1
. Pattenden, B.J. and Walker, J., J. Chem. Soc. C, 1969,
Synthesis of -chloropropionic acid. A mixture
vol. 4, p. 531.
of 1.43 g of 2,3-dichlorpropionic acid with a slight
excess of (C H ) N in acetonitrile was heated under
2. Khachatryan, R.A., Kotikyan, S.Yu., Khachi-
kyan, R.Dhz., Panosyan, G.A., Mizarkhanyan, M.R.,
and Indzhikyan, M.G., Zh. Obshch. Khim., 2003,
vol. 73, no. 10, p. 1594.
3. Tung, C.C. and Speziale, A.J., J. Org. Chem., 1963,
vol. 28, no. 6, p. 1521.
2
5 3
reflux for 1 h and then left to stand at room tempera-
ture for 3 4 days. The reaction mixture was poured
into ether, and the precipitate was filtered off and
washed with ether. The solvent was removed to obtain
1
g (94%) of -chloroacrylic acid, mp 62 63 C
4. Bernd, R., Helmut, D., and Helmut, V., DE Patent
2213734, 1972; Chem. Abstr., 1973.
(published data [4]: mp 62 63 C).
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 75 No. 12 2005