Russian Journal of General Chemistry, Vol. 73, No. 2, 2003, pp. 325 326. Translated from Zhurnal Obshchei Khimii, Vol. 73, No. 2, 2003,
pp. 349 350.
Original Russian Text Copyright
2003 by Sultangareev, Rozinov, Albanov, Voronkov.
LETTERS
TO THE EDITOR
Reactions of Polychloroethylenes with Sodium Polysulfides
in Aqueous-Alkaline Dimethylformamide
P. G. Sultangareev, V. G. Rozinov, A. V. Albanov, and M. G. Voronkov
Favorskii Irkutsk Institute of Chemistry, Siberian Division, Russian Academy of Sciences, Irkutsk, Russia
Irkutsk State University, Irkutsk, Russia
Received January 30, 2002
Reactions of tetrachloroethylene with anhydrous
sodium sulfides (Na S , Na S ) in dimethylform-
chloroethylene and sodium trisulfide in aqueous-
alkaline diethylamine, yielding diethylthioacetamide.
2
4
2 5
amide (DMF) yield polymeric compounds [1, 2].
Thioamide VI proved to be a convenient reagent
for introducing a thioxo group into chlorophospho-
nium alkyl(aryl)chlorophosphoranes and hexachloro-
phosphorates [3].
We found that tetrachloroethylene reacts with
sodium tetra- and pentasulfides in aqueous-alkaline
DMF to give condensation products [C HS ] , while
2
3 n
the reaction with sodium trisulfide produces N,N-di-
methylthioacetamide (VI) by the following scheme.
N,N-Dimethylthioacetamide (VI). To a solution
of 3 g of NaOH in 25 ml of water we added 3.2 g of
elemental sulfur, and the mixture was heated on a
water bath at 90 95 C until sulfur had dissolved com-
pletely. A solution of 2.1 g of tetrachloroethylene in
25 ml of DMF was added to the resulting solution,
and the mixture was heated at 90 95 C for 4 h, after
which it was treated with dilute hydrochloric acid to
pH 4 5. The precipitate was filtered off, the filtrate
was treated with chloroform, washed with water,
NaOH
HC(O)NMe2
HC(O)ONa + HNMe2,
I
NMe2
NaOH
Cl C=CCl + I
Cl C=C
2
2
2
NaCl
Cl
II
NMe2
H O
NMe2
Na2S3
2
Cl C=C
Cl C=C
2
2
S3Na
S2, NaOH
SH
III
IV
treated with chloroform, and dried with MgSO . The
4
NMe2 2Na2S3
NMe2
chloroform was removed, and the residue was sublimed
on a finger condenser in a water-jet-pump vacuum.
Yield 0.48 g (23%), mp 78 C. IR spectrum, , cm :
Cl CH C
CH C
2
3
S
S
1
V
VI
8
60 (C=S), 1395 1540, 1260 1420, 940 1140
+
2NaCl + Na C .
2 6
1
(NC=S) [4]. H NMR spectrum, , ppm: 2.63 s (3H,
1
3
Dimethylformamide undergoes alkaline hydrolysis
to sodium formate and dimethylamine (I) which sub-
stitutes chlorine in tetrachloroethylene to form 1,2,2-
trichloro-1-(dimethylamino)ethylene (II).
CH ), 3.28 s, 3.47 s (3H, CH N). C NMR spectrum,
3 3
, ppm: 31.70 (CH CS), 31.31, 43.06 (CH N). Found,
C
3
3
%: C 46.69; H 8.70; N 13.57; S 30.89. C H NS.
Calculated, %: C 46.56; H 8.79; N 13.57; S 31.07.
4
9
The nucleophilic attack of Na S on its inter-
N,N-Diethylthioacetamide. To a solution of 3.2 g
of elemental sulfur and 3 g of NaOH in 25 ml of
water, heated to 90 95 C, we added 2.1 g of tetra-
chloroethylene in 25 ml of diethylamine. The mixture
was heated for 14 h and then treated with hydrochloric
acid to pH 4 5 and filtered. The filtrate was treated
with chloroform, and the extract was dried with
2
3
mediate gives rise to compound III which hydrolyzes
to unsaturated thiol IV. The latter rearranges to di-
chlorothioacetamide V which is then reduced to amide
VI.
With trichloroethylene instead of tetrachloroethyl-
ene, the yield of amide VI is not improved appreci-
ably.
MgSO . The chloroform was removed, and the residue
4
was distilled in a vacuum. Yield 0.31 g (15%), bp 99
100 C (3 mm), n2 1.5381. IR spectrum, , cm :
0
1
The formation of compound I and its participation
in the reaction was proved by the reaction of tetra-
D
1
1505, 1025 1280 (NC=S), 840 (C=S). H NMR spec-
1
070-3632/03/7302-0325$25.00 2002 MAIK Nauka/Interperiodica
Sultangareev
