REACTION OF HALOACRYLIC ACIDS WITH PHOSPHORUS NUCLEOPHILES
1509
We failed to obtain substitution products in the
reactions of triethylamine with -chloro(bromo)-
methacrylic acids. In both cases, triethylamine hydro-
halides formed (yields 36.6 and 23.3%, respectively.
This result evidently points to intermediate carbene
formation.
methacrylic acid in 5 ml of acetonitrile was heated
for 6 h. The precipitate was filtered off, washed with
acetonitrile, and dried in a vacuum to obtain 2.5 g
(65.4%) (2-carboxyallyl)triphenylphosphonium chlo-
1
ride (III), mp 236 C. H NMR spectrum (CD3OD),
, ppm: 7.6 7.85 m (15H, C6H5), 5.8 and 6.2 d (1HE,
4
4
=CH2, JPH 6.9 Hz, 1HZ, =CH2, JPH 6.3 Hz), 4.4 d
+
2
EXPERIMENTAL
(2H, PCH2, JPH 15.3 Hz). Found, %: Cl 9.20.
C22H20ClO2P. Calculated, %: Cl 9.28.
The NMR spectra were recorded on a Varian
Mercury-300 spectrometer (300 MHz) against internal
TMS.
b. At room temperature. A solution of 1.31 g of tri-
phenylphosphine and 0.6 g of -chloromethacrylic
acid in 15 ml of benzene was left to stand for 14 days.
Then the reaction mixture was treated as described
above to give 0.65 g (32%) of (2-carboxypropenyl)tri-
phenylphosphonium chloride (IV), mp 163 163 C.
Reaction of triphenylphosphine with -chloro-
acrylic acid. a. At elevated temperature. A solution of
1.31 g of triphenylphosphine and 0.53 g of -chloro-
acrylic acid in 5 ml of benzene was heated for 3 h at
50 C. The solution was decanted, and the tarry
residue was treated with ether. The ethereal extract
was filtered, the precipitate was dissolved in aceto-
nitrile and precipitated with ether to obtain 1.3 g
(71%) of (2-carboxyvinyl)triphenylphosphonium
1H NMR spectrum (DMSO-d6), , ppm: 7.7 8 m
2
(15H, C6H5), 7.4 d (1H, CH=, JPH 22.2 Hz), 1.8 (3H,
CH3). Found, %: Cl 9.35. Triphenylphosphine, 0.8 g
(61%), was recovered from the benzene solution.
Reaction of triphenylphosphine with -bromo-
methacrylic acid. a. At elevated temperature. The
reaction was carried out similarly to the reaction of tri-
phenylphosphine with -chloromethacrylic acid (pro-
cedure a). From 3.93 g of triphenylphosphine and
2.47 g of -bromomethacrylic acid in 10 ml of aceto-
nitrile 5.5 g, an inseparable mixture of three products
1
chloride, mp 165 166 C. H NMR spectrum (DMSO-
+
d6), , ppm: 7.8 m (15H, C6H5), 8.3 d.d (1H, PHC=,
2JPH 20 Hz), JHH 16.6 Hz), 6.8 d.d (1H, +P C=C Hcis,
2
3JPH 21.0 Hz, JHH 16.65 Hz). Found, %: Cl 9.40.
C21H19ClO2P. Calculated, %: Cl 9.63. Triphenyl-
phosphine, 0.3 g (22.9%), was obtained from the
benzene solution, mp 80 C.
1
was obtained. According to the H NMR spectrum, it
contained 40% of (2-carboxyallyl)triphenylphos-
phonium bromide (V). 1H NMR spectrum (DMSO-d6),
, ppm: 7.4 8 m (15H, C6H5), 5.8 and 6.4 d (1HE,
b. At room temperature. A solution of 1.31 g of tri-
phenylphosphine and 0.53 g of -chloroacrylic acid
in 18 ml of benzene was left to stand for 14 days. The
solution was decanted, and the residue was washed
with anhydrous ether and dried in a vacuum to obtain
1.66 g (90%) of (2-carboxyvinyl)triphenylphospho-
nium chloride (I), mp 165 166 C. This sample
showed no melting point depression when mixed with
4
4
=CH2, JPH 6.5 Hz and 1$HZ, =CH2, JPH 6.3 Hz),
2
4.7 d (2H, CH2, JPH 15.3 Hz).
b. At room temperature. The reaction was carried
out similarly to the reaction of triphenylphosphine
with -chlorometacrylic acid (procedure b). From
1.31 g of triphenylphosphine and 0.82 g of -bromo-
methacrylic acid in 15 ml of benzene, 1.49 g (70%)
of (2-carboxypropenyl)triphenylphosphonium bromide
1
the sample obtained by procedure a. The H NMR
spectrum is similar to the above. Found, %: Cl 9.45.
1
c. In the presence of hydrochloric acid. A solution
(VI) was obtained, mp 203 204 C. H NMR spec-
of 1.31 g of triphenylphosphine and 0.53 g of
-
trum (DMSO-d6), , ppm: 7.75 8 m (15H, C6H5),
7.5 d (1H, CH=, JPH 22.2 Hz), 1.8 s (3H, CH3).
Found, %: Br 18.50. C22H20BrOP. Calculated, %:
Br 18.73.
chloroacrylic acid in 0.9 ml of 32.5% hydrochloric
acid was heated on a boiling water bath until gas
evolution began. After addition of 20 ml of water, the
reaction mixture was extracted with ether and then
with chloroform. The combined chloroform extracts
were treated with anhydrous ether, and the precipitate
was filtered off and dried in a vacuum to give 1.6 g
(87%) of (2-carboxyvinyl)triphenylphosphonium
Reaction of diphenylphosphine oxide with
-
chloroacrylic acid. a. At elevated temperature. A
mixture of 1 g of diphenylphosphine oxide and 0.5 g
of -chloroacrylic acid was refluxed in benzene for
5.5 h. The solvent was removed, and the solid residue
was dissolved in chloroform and precipitated with
ether to obtain 0.75 g (50%) of 2-chloro-3-(diphenyl-
1
chloride (I), mp 165 166 C. The H NMR spectrum
is similar to the above. Found, %: Cl 9.50.
1
Reaction of triphenylphosphine with -chlorome-
thacrylic acid. a. At elevated temperature. A solution
of 2.62 g of triphenylphosphine and 1.2 g of -chloro-
phosphinoyl)propionic acid (II), mp 145 C. H NMR
spectrum (DMSO-d6), , ppm: 7.5 7.9 m (10H, C6H5),
4.5 m (1H, CHCl, JPH 11.1 Hz, JHH 11.1 Hz), 2.9
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 73 No. 10 2003