6
12
ROZENTSVEIG et al.
gyl bromide. We anticipated generation of the corre-
sponding organozinc compounds in situ. In fact, this
procedure was less laborious, and the yield of target
sulfonamides II and III was considerably higher. Thus
one-pot procedure involving preparation of organozinc
compounds in situ is more advantageous than the use
of preliminarily prepared organozinc compounds.
of compound I, 2.42 g (0.02 mol) of allyl bromide,
1.30 g (0.02 mol) of zinc dust, 10 ml of THF, and
10 ml of benzene was stirred first for 0.5 h at 60°C and
then for 5 h at 20°C. The mixture was then treated with
20 ml of 30% acetic acid, the organic phase was
separated, washed with water (3×30 ml), dried over
Na SO , and evaporated, and the solid residue was re-
2
4
crystallized from hexane. Yield 4.94 g (68%), mp 112–
It should be specially emphasized that in the ex-
amined reactions we did not observe formation of
–
1
1
15°C. IR spectrum (KBr), ν, cm : 3267 (NH), 1644
1
(
C=C), 1340, 1165 (SO ). H NMR spectrum, δ, ppm:
4
-chloro-N-(2,2,2-trichloroethyl)benzenesulfonamide
2
as by-product via reduction of the C=N bond. Further-
more, the reaction mixtures contained no products that
could be formed via transformations of the trichloro-
methyl group in Schiff base I or sulfonamides II and
III. We failed to obtain compounds II and III by reac-
tion of I with allylmagnesium bromide or propargyl-
magnesium bromide. In these cases, the reactions in-
volved transformations of the trichloromethyl group,
cleavage of the C–N bond with liberation of 4-chloro-
benzenesulfonamide, and considerable tarring.
2.32 m and 2.75 m (1H each, CH
), 4.12 m (1H,
2
3
NHCH); 4.64, 4.93, 5.38 (3H, CH=CH
, JAB = 17.0,
AC = 10.0, JBC = 1.2 Hz); 7.63, 7.81 (4H, C
2
3
2
J
H ,
6 4
3
13
AA′BB′); 8.76 d (1H, NH, J = 8.8 Hz). C NMR
spectrum, δ , ppm: 35.98 (CH ), 69.19 (NHCH),
103.63 (CCl ), 119.19 (=CH ); 129.18, 129.61, 137.87,
141.67 (C H ); 133.03 (CH). Found, %: C 36.74;
C
2
3
2
6
4
H 3.03; Cl 38.93; N 3.69; S 8.69. C H Cl NO S. Cal-
11
11
4
2
culated, %: C 36.39; H 3.05; Cl 39.06; N 3.86; S 8.83.
4
-Chloro-N-(1,1,1-trichloropent-3-yn-2-yl)ben-
Thus the use of organozinc reagents in reactions
with N-(arylsulfonyl) trichloroacetaldehyde imines is
more appropriate than the use of organomagnesium or
other more active organometallic compounds which
act as strong reducing agents and are capable of initiat-
ing side processes. Analogous results were obtained
while studying similar transformations of alkyl tri-
chloroethylidenecarbamates [17].
zenesulfonamide (III) was synthesized in a similar
way from 2.42 g (0.02 mol) of prop-2-ynyl bromide.
The product was purified by washing with cold diethyl
ether until its color disappeared. Yield 3.25 g (45%),
1
mp 119–121°C. H NMR spectrum, δ, ppm: 2.62 s
(
(
1H, ≡CH), 2.93 m and 2.97 m (1H each, CH ), 4.29 m
2
1H, CH); 7.63, 7.86 (4H, C H , AA′BB′); 9.00 d (1H,
6
4
3
13
NH, J = 8.9 Hz). C NMR spectrum, δ , ppm: 21.92
C
The structure of amides II and III was confirmed
by spectral methods and elemental analyses. The NCH
proton in compounds II and III resonated in their
(CH
(CCl
%: C 36.72; H 2.48; Cl 39.50; N 3.69; S 8.71.
Cl NO S. Calculated, %: C 36.59; H 2.51;
2
), 68.28 (≡CH), 74.09 (NCH), 78.92 (≡C), 101.96
), 128.74, 129.15, 137.46, 141.15 (C ). Found,
H
6 4
3
1
H NMR spectra as a complex multiplet due to spin–
C
11
H
9
4
2
spin couplings with diastereotopic protons in the
neighboring methylene group.
Cl 39.27; N 3.88; S 8.88.
The IR spectra were recorded on a Bruker IFS-25
1
13
The presence of a trichloromethyl group, NH
group, and multiple bonds in the molecules of sulfon-
amides II and III makes these compounds promising
as reagents for subsequent transformations, including
preparation of various functionalized acyclic deriva-
tives of the sulfonamide series and heterocyclic
compounds.
spectrometer. The H and C NMR spectra were meas-
ured from solutions in DMSO-d on a Bruker DPX-
400 spectrometer at 400.61 and 100.13 MHz, respec-
tively, using tetramethylsilane as internal reference.
6
REFERENCES
1
2
3
. Rozentsveig, I.B., Levkovskaya, G.G., Mirskova, A.N.,
and Kashik, T.V., Russ. J. Org. Chem., 2000, vol. 36,
p. 1760.
We are now trying to optimize the procedure for the
preparation of compounds II and III and studying their
reactivity and biological activity.
. Rozentsveig, I.B., Levkovskaya, G.G., Rozentsveig, G.N.,
Mirskova, A.N., Krivdin, L.B., Larina, L.I., and Alba-
nov, A.I., Tetrahedron Lett., 2005, vol. 46, p. 8889.
4
-Chloro-N-(2,2,2-trichloroethylidene)benzenesul-
fonamide (I) was synthesized according to the proce-
dure described in [9].
. Rozentsveig, I.B., Popov, A.V., Mirskova, A.N., and
Levkovskaya, G.G., Russ. J. Org. Chem., 2007, vol. 43,
p. 1559.
4
-Chloro-N-(1,1,1-trichloropent-4-en-2-yl)ben-
zenesulfonamide (II). A mixture of 6.42 g (0.02 mol)
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 47 No. 4 2011
Rozentsveig
