Reaction of methyl esters of P(IV) acids with polychlorinated hydrocarbons [4]

Full text of DOI:10.1007/s11176-005-0157-6

Russian Journal of General Chemistry, Vol. 74, No. 8, 2004, pp. 1295 1296. Translated from Zhurnal Obshchei Khimii, Vol. 74, No. 8, 2004,
pp. 1398 1399.
Original Russian Text Copyright
2004 by M. Gazizov, Karimova, Nikolaeva, Pudovik, K. Gazizov, Khairullin.
LETTERS
TO THE EDITOR
Reaction of Methyl Esters of P(IV) Acids
with Polychlorinated Hydrocarbons
M. B. Gazizov, R. F. Karimova, V. G. Nikolaeva,
M. A. Pudovik, K. M. Gazizov, and R. A. Khairullin
Kazan State Technological University, Kazan, Tatarstan, Russia
Arbuzov Institute of Organic and Physical Chemistry, Kazan Research Center,
Russian Academy of Sciences, Kazan, Tatarstan, Russia
Received December 5, 2003
We were the first to effect dehydrochlorination of
with phosphinate Ic and for 20 h at 160 C and 170 C
with phosphonate Ib and phosphate Ia, respectively. It
is known that group successive replacement in com-
pounds I of the electron-acceptor MeO on alkyls, i.e.
in going from Ia to Ib and further to Ic, the first
ionization potential tends to decrease: 10.81, 10.53,
pentachloroethane (IIa) and heptachloropropane (IIb)
with methyl esters of phosphoric (Ia), methylphos-
phonic (Ib), and diethylphosphinic (Ic) acids to obtain
perchloroethene (IIIa) and perchloropropene (IIIb) in
high yields. Therewith, the methyl esters of P(IV)
acids transformed into diethylphosphinic acid (IVc),
hydrogen dimethyl phosphate (IVa), and hydrogen
methyl methylphosphonate (IVb).
1
2
and 10.01 (10.20, R = R = Me) eV, respectively
1 4]. The reactivity of these compounds increases in
[
the order Ia < Ib < Ic, implying that the P(IV) esters
acts as electron-donors in the reaction in hand. There-
fore, we suppose that the reaction begins with nucleo-
philic attack of the phosphoryl oxygen atom on the
hydrogen atom of 1H-perchloroalkane II. Quasiphos-
phonium intermediate V is stabilized via elimination
of methyl chloride to form acid IV.
The reaction between compounds I and IIa was
1
studied by dynamic H NMR spectroscopy. Spectra
were measured every 5 h, following the intensity of
the methyl proton signal of pentachloroethane (
.5 ppm). The signal disappeared completely after
6
heating of a 1:1 reagent mixture for 10 h at 150 C
1
2
+
1 2
R R (MeO)P=O H CCl CXCl(X) Cl
Cl Me O P (OH)R R + CCl =CClX
2
2
Ia Ic
IIa, IIb
V
1
2
R R P(O)(OH) + CCl =CClX + MeCl
2
IVa IVc
IIIa, IIIb
1
2
1
2
I, IV, R = R = MeO (a), Et (c); R = Me, R = MeO (b); II, III, X = Cl (a), CCl (b).
3
Reaction of compounds I and II. A 1:1 mixture
of compounds I and II was heated in a sealed ampule
until the methine proton signal at 6.5 ppm disap-
peared completely from the H NMR spectrum of the
reaction mixture. After that the reaction mixture was
exposed to high vacuum to separate volatile reaction
the trap gave compounds IV and III.
a. A mixture of 1.72 g of trimethyl phosphate and
.48 g of compound IIa was heated at 170 C for 20 h
2
1
to obtain 0.81 g (53%) of hydrogen dimethyl phosphate
(IVa), bp 128 129 C (0.4 mm Hg), n2 1.4065 {pub-
0
D
2
0
lished data: bp 79 80 C (0.001 mm Hg), n 1.4049
D
1
products which were collected in a liquid nitrogen trap. [5]}. H NMR spectrum (CDCl ), , ppm: 3.51 d (6H,
Distillation of the residue and the condensate from
3
3
MeO, J 12.5 Hz), 12.1 s (1H, POH).
1 ppm.
PH
P
1
070-3632/04/7408-1295 2004 MAIK Nauka/Interperiodica

1296
GAZIZOV et al.
Found P, %: 24.23. C H O P. Calculated P, %: 24.57.
(100 and 25.2 MHz) spectrometers, internal reference
TMS. The 31P NMR spectra were obtained on an RYa-
2303 spectrometer (21 MHz), external reference 85%
H PO .
2
7
4
Tetrachloroethene (IIIa), 1.40 g (69%), was isolated,
2
0
bp 122 123 C, n 1.5025 {published data: bp 121 C,
D
2
0
n
1.5055 [6]}.
D
3
4
b. A mixture of 4.91 g of dimethyl methylphos-
ACKNOWLEDGMENTS
The work was financially supported by the Russian
Foundation for Basic Research (project no. 03-03-
2547).
phonate and 8.01 g of compound IIa was heated at
60°C for 20 h to obtain 2.19 g (50%) of hydrogen
methyl methylphosphonate (IVb), bp 98 99 C
0.03 mm Hg), n 1.4223. HNMR spectrum (CDCl ),
1
2
0
1
(
D
3
3
2
,
ppm: 1.27 d (3H, Me, J 18 Hz), 3.63 d (3H,
POMe, J 12 Hz), 12.1 s (1H, POH). Found P, %:
PH
3
PH
REFERENCES
2
8.01. C H O P. Calculated P, %: 28.15. Compound
2 7 3
2
0
IIIa, 4.73 g (72%), was obtained, bp 122 123 C, n
D
1
. Zverev, V.V. and Villem, Ya.Ya., Zh. Strukt. Khim.,
980, vol. 21, no. 1, p. 30.
1
.5020.
c. A mixture of 3.4 g of methyl diethylphosphinate
and 5.06 g of compound IIa was heated at 150 C for
1
2. Vovna, V.I., Lopatin, S.N., Pettsol’d, R., and Vile-
sov, F.I., Khim. Vys. Energ., 1975, vol. 9, no. 9,
p. 9.
1
1
0 h too obtain 1.89 g (62%) of acid IVc, bp 115
2
0
1
16 C (0.05 mm Hg), n 1.4535. H NMR spectrum
D
2
(
CDCl ), , ppm: 1.13 d.t (6H, CH CH , J 20,
JHH 7.2 Hz), 1.66 d.q (4H, CH CH , J 14, J
3
2
3
PH
3
2
3
3
. Zverev, V.V., Zh. Obshch. Khim., 1984, vol. 54, no. 6,
p. 1265.
2
3
PH
HH
7
2
.2 Hz), 12.1 s (1H, POH).
55 ppm. Found P, %:
P
5.44. C H O P. Calculated P, %: 25.37. Compound
4
11
2
2
0
4. Zverev, V.V., Villem, Ya.Ya., Bel’skii, V.E., and Ki-
taev, Yu.P., Khimiya i prakticheskoe primenenie
kremnii- i fosfororganicheskikh soedinenii (Chemistry
and Practical Application of Organosilicon and Organo-
phosphorus Compounds), Leningrad: Leningr. Tekhnol.
Inst., 1979, pp. 126 132.
IIIa, 3.09 g (75%), was obtained, bp 122 123 C, n
D
1
.5025.
d. A mixture of 2.84 g of methyl diethylphosphi-
nate and 5.94 g of compound IIb was heated at 180 C
for 14.5 h to obtain 1.95 g (77%) of acid IVc, bp
2
0
1
15 116 C (0.3 mm Hg), n 1.4560. Hexachloro-
D
propene (IIIb), 2.89 g (56%), was obtained, bp 95
5. Nifant’ev, E.E., Khimiya fosfororganicheskikh soedi-
nenii (Chemistry of Organophosphorus Compounds),
Moscow: Mosk. Gos. Univ., 1971.
2
0
13
9
7 C (20 mm Hg), n 1.5460. C NMR spectrum
CDCl3), C, ppm: 133.2 s (=CCl), 128.5 s (=CCl2),
D
(
9
3.5 s (CCl3).
6
. Rabinovich, V.A. and Khavin, Z.Ya., Kratkii khimi-
cheskii spravochnik (Concise Chemical Handbook),
Moscow: Khimiya, 1977.
The H and 13C NMR spectra were measured on
1
Bruker WP-80 (80 and 20.1 MHz) and Tesla BS567A
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 74 No. 8 2004