N-CHLORO-N-(1,2,2,2-TETRACHLORO- AND 1,2,2-TRICHLOROETHYL)SULFONAMIDES
1419
genation [6]. We failed to detect radical B in the reac-
tion mixture by physical methods. Also, unsuccessful
attempts to synthesize addition products like II were
reported. Thus, no proofs for any of the above reaction
paths were obtained.
In the present work we succeeded in obtaining for
the first time products of addition of N,N-dichloro-
sulfonamides Ia Ic to 1,2-dichloroethylene and 1,1,2-
trichloroethylene, N-chloro-N-(1,2,2-trichloro- and
1,2,2,2-tetrachloroethyl)sulfonamides IIa IId. We
found that strict adherence to temperature conditions
is the main factor ensuring successful results. Com-
pounds IIa IId were synthesized by reaction of N,N-
dichloro amides Ia and Ib with trichloroethylene at
a temperature not exceeding 15 C; the reaction lasted
several days. The addition also occurs in the dark at
the same temperature, but it takes a longer time.
Thus we were the first to demonstrate that N,N-di-
chlorosulfonamides react with 1,2-dichloroethylene
and trichloroethylene at a temperature not exceeding
20 C in the absence of a catalyst through intermediate
formation of unstable adducts which undergo de-
chlorination to afford N-polychloroethylidenesulfon-
amides. It should be noted that our results do not rule
out reaction path involving 1,3-chlorotropic rearrange-
ment in the reaction of N,N-dichloro amides with
1,2-polyhaloethenes on heating or irradiation.
EXPERIMENTAL
The IR spectra were recorded on a Specord 75IR
spectrometer from samples pelleted with KBr or dis-
1
persed in mineral oil. The H and 13C NMR spectra
were obtained on Bruker DPX-400 and Varian VXR-
500S instruments using HMDS as internal reference.
The addition of N,N-dichlorotrifluoromethane-
sulfonamide (Ic) to 1,2-dichloroethylene and 1,1,2-tri-
chloroethylene occurred on exposure to light at room
temperature using 3 6 equiv of polychloroethene; the
reaction was complete in 15 min, and the yields of
amides IIc and IId were quantitative. The process
was accompanied by heat evolution. No effect of the
isomeric composition of 1,2-dichloroethylene was
observed (both pure cis and trans isomers and their
mixture were used).
N-Chloro amides IIa IId are unstable. On heating
above 20 C, as well as on storage, they are converted
into the corresponding Schiff bases IIIa IIId. Pre-
sumably, the low stability of compounds like II is
responsible for the failure to obtain the respective
addition products from N,N-dichloro amides Ia and
Ib and 1,2-dichloroethylene. For the same reason,
only amide IIb was isolated in the pure state. Com-
pound IIa was isolated as a mixture with Schiff base
IIIa, and trifluoromethanesulfonamide derivatives IIc
and IId were obtained as solutions in haloethenes.
N-Chloro-N-(1,2,2,2-tetrachloroethyl)benzene-
sulfonamide (IIa). N,N-Dichlorobenzenesulfonamide
(Ia), 2.26 g (0.01 mol), was dissolved in 5.5 ml
(0.06 mol) of trichloroethylene, and the mixture was
kept for 24 h at 10 15 C and then for 3 days at
15 C. The precipitate was filtered off, dried under
reduced pressure, and analyzed by NMR spectroscopy.
1
According to the H NMR data, the product was
a mixture of compounds IIa and IIIa at a ratio of
1
1:1; yield of IIa 37%. H NMR spectrum (CDCl3),
, ppm: IIa: 7.23 s (1H, CHCl), 7.47 7.75 m (5H,
Harom); IIIa: 8.40 s (1H, N CH), 7.82 8.05 m
(5H, Harom).
N,4-Dichloro-N-(1,2,2,2-tetrachloroethyl)ben-
zenesulfonamide (IIb). N,N,4-Trichlorobenzenesul-
fonamide (IIb), 2.62 g (0.01 mol), was dissolved in
5.5 ml (0.06 mol) of trichloroethylene, and the solu-
tion was kept for 4 days at 10 15 C and was then
treated as described above. Yield 3.33 g (85%),
1
mp 122 125 C (decomp.). IR spectrum, , cm :
1180, 1380 (SO2); 2980 (C Haliph), 3085 3090
The formation of N-chloro-N-(polychloroethyl)-
sulfonamides IIa IId was proved by NMR data.
(C Harom). 1H NMR spectrum (CDCl3), , ppm:
7.24 s (1H, CHCl), 7.53 and 7.91 (4H, AA BB , C6H4).
13C NMR spectrum (CDCl3), C, ppm: 85.52 (CHCl);
98.49 (CCl3); 129.33, 131.21, 132.40, 142.36 (C6H4).
Found, %: C 24.22; H 1.30; Cl 53.85; N 3.77; S 8.05.
C8H5Cl6NO2S. Calculated, %: C 24.52; H 1.29;
Cl 54.28; N 3.57; S 8.18.
1
In the H NMR spectra of amides IIa IId we observ-
ed characteristic singlets at 6.4 7.2 ppm (IIa IIc) or
a doublet at 6.4 ppm (IId), which belong to the
CHCl proton. The corresponding carbon signal
appears in the 13C NMR spectra of IIa IId at
80
C
85 ppm. In addition, the spectra of IIa IId contained
signals from aromatic rings or CF3 group and from
the CXCl2 moiety. The structure of amide IIb, which
was isolated as individual substance, was also con-
firmed by IR spectroscopy and elemental analysis.
The spectral parameters and physical constants of
Schiff bases IIIa IIId were in agreement with those
reported in [7 9].
N-Chloro-N-(1,2,2,2-tetrachloroethyl)trifluoro-
methanesulfonamide (IIc). Trichloroethylene, 0.9 ml
(0.01 mol), was added to 0.44 g (0.002 mol) of N,N-
dichlorotrifluoromethanesulfonamide (Ic) [10], and
the solution was kept for 5 15 min on exposure to
direct sunlight, maintaining the temperature below
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 39 No. 10 2003
Kondrashov
