Synthesis of N-(2-benzene-2,2-dichloroethylidene)-4-chlorobenzenesulfonamide and N-(2-benzene-2,2-dichloroethylidene)-4-methylbenzenesulfonamide

Article abstract of DOI:10.1023/A:1012347516916

In reaction of N,N-dichloro-4-chlorobenzene-and N,N-dichloro-4-methylbenzenesulfonamides with phenylacetylene were obtained in good yield N-(2-benzene-2,2-dichloroethylidene)arenesulfonamides. The latter undergo nucleophilic addition of water, ethanol, an

Full text of DOI:10.1023/A:1012347516916

Russian Journal of Organic Chemistry, Vol. 37, No. 2, 2001, pp. 284 287. Translated from Zhurnal Organicheskoi Khimii, Vol. 37, No. 2, 2001,
pp. 297 300.
Original Russian Text Copyright
2001 by Drozdova, Mirskova.
Synthesis of N-(2-Benzene-2,2-dichloroethylidene)-4-
chlorobenzenesulfonamide and N-(2-Benzene-2,2-
dichloroethylidene)-4-methylbenzenesulfonamide
T. I. Drozdova and A. N. Mirskova
Irkutsk Institute of Chemistry, Siberian Division, Russian Academy of Sciences, Irkutsk, 664033 Russia
Received January 14, 1999
Abstract In reaction of N,N-dichloro-4-chlorobenzene- and N,N-dichloro-4-methylbenzenesulfonamides
with phenylacetylene were obtained in good yield N-(2-benzene-2,2-dichloroethylidene)arenesulfonamides.
The latter undergo nucleophilic addition of water, ethanol, and arenesulfonamides.
We reported formerly [1] on reaction of N,N-di-
chlorobenzenesulfonamide with phenylacetylene yield-
The yield of imines IIIa, b is strongly affected
by the temperature at the initial reaction period: the
increase over 20 C reduces the yield of imines by
15 20% with simultaneous growth of side products
content: of 1,1-di(arenesulfonamido)-2-phenyl-2,2-
dichloroethanes (IVa, b) to 12 14%, and of arene-
sulfonamides (Va, b) to 15 20%. To obtain high
yields of compounds IIIa, b it is desirable to add
slowly the phenylacetylene (II) to a solution of
dichloroamides Ia, b in CCl4 avoiding overheating
above 20 C.
ing
N-(2-benzene-2,2-dichloroethylidene)benzene-
sulfonamide alongside the other products arising from
further transformations and reactions of the latter
imine. A.A.Petrov et al [2] obtained N-(2-benzene-
2,2-dichloroethylidene)-4-chlorobenzenesulfonamide
in lower yield by prolonged (25 h) heating of a mix-
ture containing phenylacetylene and N,N-dichloro-
benzenesulfonamide; the other reaction products were
not thoroughly investigated. Aiming at further
investigation of reactions between phenylacetylene
and N,N-dichloroarenesulfonamides and at refining
the synthetic procedures for the above imines we
studied the effect of reaction conditions of N,N-di-
chloro-4-chlorobenzene- and N,N-dichloro-4-methyl-
benzenesulfonamides (Ia, b) with phenylacetylene
(II).
The changed order of reagents mixing, namely,
addition of dichloroamides Ia, b in CCl4 solution to
phenylacetylene also results in strong reduction of
imines IIIa, b yield due to proceeding of the side
processes providing predominantly sulfonamides
Va, b. After the mixing of reagents is completed the
reaction mixture is heated to 55 60 C and stirred for
about 1 h. The longer heating of the reaction mixture
gives rise to side processes to afford amides IVa, b,
Va, b at the expense of decrease in the yield of the
target products IIIa, b.
ArSO2NCl2
+
C6H5C CH
ArSO2N= CHCCl2C6H5
Ia,b
II
IIIa,b
(ArSO2NH)2CHCCl2C6H5 + ArSO2NH2
IVa,b Va,b
The previously obtained data [1] on the effect of
reagents ratio on the yield of reaction products are in
agreement with those obtained in this study of reac-
tion between dichloroamides Ia, b and phenylacetyl-
ene (II). Thus at two-fold excess of phenylacetylene
(II) the reaction furnishes imines IIIa, b in sufficient-
ly high yield (70 75%). The rise in the yield by
7 9% is attained at increasing the excess of phenyl-
acetylene (II) from 2-fold to 4-fold. Further increase
in phenylacetylene excess to 6-fold does not affect the
yield of compounds IIIa, b. The attempt to carry out
the reaction at equimolar reagents ratio and initiation
by UV-irradiation at 30 C did not result in high yield
Ar = 4-ClC6H4 (a), 4-CH3C6H4 (b).
It was established that the reaction of N,N-di-
chloro-4-chlorobenzene- or N,N-dichloro-4-methyl-
benzenesulfonamides (Ia, b) with phenylacetylene
(II) in 1: 4 ratio proceeded under inert atmosphere
(nitrogen or argon) in anhydrous carbon tetrachloride
for 0.5 1 h at 15 20 C and 0.5 1 h at 55 60 C to
afford
N-(2-benzene-2,2-dichloroethylidene)arene-
sulfonamides (IIIa, b) in 80 and 82% yields,
respectively. As side products formed amides IVa, b
in 6 8% yield and amides Va, b in 5 7% yield.
1070-4280/01/3702-0284$25.00 2001 MAIK Nauka/Interperiodica

SYNTHESIS OF N-(2-BENZENE-2,2-DICHLOROETHYLIDENE)-4-...
285
Table 1 Yields, melting points, and elemental analyses of N-arenesulfonylimines IIIa, b and N-substituted
arenesulfonamides IVa, b, VIa, b, VIIa, b
Compd. Yield,
mp,
C
Found, %
Cl
Calculated, %
Cl
no.
%
Formula
C
H
N
S
C
H
N
S
IIIa
82
80
67
65
79
78
78
74
104 105a 46.24 2.74 29.24 3.83
8.79 C14H10Cl3NO2S 46.54 2.79 29.06 3.88
9.54 C15H13Cl2NO2S 52.79 3.84 20.51 4.11
8.86
9.38
IIIb
IVa
IVb
VIa
VIb
VIIa
VIIb
105 106
217 219
200 202
124 126
115 119
86 88
52.37 3.68 20.29 4.37
43.09 3.09 25.52 5.03 11.52 C20H16Cl4N2O4S2 43.48 2.92 25.34 5.07 11.59
50.98 4.61 13.62 5.29 12.28 C22H22Cl2N2O4S2 51.56 4.33 13.66 5.47 12.50
44.56 3.40 27.44 4.06
49.91 4.22 19.68 3.80
47.34 3.78 25.21 3.67
51.93 4.64 17.73 3.56
8.27 C14H12Cl3NO3S 44.33 3.79 27.68 3.70
8.88 C15H15Cl2NO3S 50.14 4.21 19.48 3.90
7.35 C16H16Cl3NO3S 47.18 3.96 25.78 3.44
8.03 C17H19Cl2NO3S 52.58 4.93 18.26 3.61
8.44
8.91
7.86
8.26
89 91
a
mp 103.5 C [2].
of imines IIIa, b. These compounds were isolated in
25 to 28% yield. Under these reaction conditions a
stronger chlorine liberation was observed.
bending vibrations of bonds in the following regions,
cm : 1635 and 1640 (C=N), 1170 and 1340
(O=S=O), 1450 and 1455 (C=Carom), 3080
(=C Harom), 760 820 (C Cl) respectively.
1
We did not observe under our reaction conditions a
formation of 1-(4-chlorophenylsulfonamido)-2-chloro-
2-phenylethene; in [2] it was obtained as presumed
due to intramolecular 1,3-migration of chlorine in the
initially arising adduct, 1-[N-chloro-N-(4-chloro-
phenyl)sulfonamido]-2-chloro-2-phenylethene.
1
In the H NMR spectra (in DMSO-d6) of imines
IIIa, b alongside the signals of the aromatic rings in
the 7.40 7.87 region are observed the singlets of the
methine protons at 8.25 and 8.21 ppm respectively,
and also a singlet of a methyl group in compound
1
IIIb at 2.38 ppm. In the H NMR spectrum of com-
Thus under experimental conditions found we
succeeded to get an yield of imine IIIa by 15%
higher than in [2] and to reduce the reaction time
from 25 to 1.5 2 h. Under the same conditions we
also obtained in high yield and high purity imine
IIIb.
pound IIIa in CDCl3 the singlet of the methine
proton appears at 8.51 ppm. The spectral char-
acteristics of compound IIIa obtained in [2], namely
1
the presence in the H NMR spectrum (in CDCl3) of
two peaks belonging to methine protons at 8.67 and
8.49 ppm in 1: 5 ratio, were not explained by Petrov
et al. Probably the signal at 8.67 ppm originated from
NH group of amide VIa that might have formed if
under conditions of the reaction in [2] were present
traces of moisture. In the 1H NMR spectrum (in
DMSO-d6) of specially prepared compound VIa
appeared a doublet signal at 8.56 ppm from the
proton of NH group. To our regret, due to the low
solubility of compound VIa in CDCl3 we failed to
compare the spectral data with those published in [2].
The formation of N-arenesulfonylimines IIIa, b
occurs apparently along the mechanism previously
assumed in [1, 2], namely, by 1,3-migration of
chlorine
in
the
initially
arising
adduct
ArSO2NClCH= CClC6H5. The resulting from the
reaction amides Va, b in the course of the process
add across the azomethine bond of compounds IIIa, b
to provide amides IVa, b.
The compounds synthesized are colorless
crystalline substances, well soluble in dimethyl
sulfoxide, dimethylformamide, acetone, chloroform,
sparingly soluble in benzene, ethyl ether, insoluble
in hexane.
It was previously demonstrated that the azomethine
bond of N-benzenesulfonylimine of dichlorophenyl-
acetic aldehyde was highly electrophilic toward
proton-donor reagents (water, alcohols. carboxylic
acids, and amides [1 4], but reactivity of imine IIIa
was revealed only by one example [2]. N-(2-Benzene-
2,2-dichloroethylidene)-4-chlorobenzenesulfonamide
and N-(2-benzene-2,2-dichloroethylidene)-4-methyl-
benzenesulfonamide (IIIa, b) prepared by us add at
heating across the N=C bond water, ethanol, arene-
Azomethine structure of compounds IIa, b was
proved by NMR and IR spectroscopy; the composi-
tion was confirmed by elemental analysis (Table 1).
In the IR spectra of compounds IIIa, b appear
characteristic absorption bands from stretching and
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 37 No. 2 2001

286
DROZDOVA, MIRSKOVA
Table 2. IR and 1H NMR spectra of N-substituted arensulfonamides IVa, b, VIa, b, VIIa, b
1
Compd.
no.
1H NMR spectrum, , ppm, J(NH CH)
IR spectrum, a, cm
NH
H (arom)
CH
CH2
CH3
J, Hz
NH
=CH
C=C
SO2
Alk
(arom) (arom)
IVa
IVb
VIa
VIb
VIIa
8.34 d 7.41 7.88 m 5.35 d
8.28 d 7.29 7.67 m 5.38 d
8.56 d 7.53 7.81 m 5.44 d
8.33 d 7.55 7.74 m 5.42 d
9.2
3220,
3280
3220,
3280
3250,
3270
3245,
3270
3230
3050,
3070
3045,
3075
3042
1480,
1420
1475
1165,
1340
1175,
1340
1160,
1320
1160,
1320
1180,
1325
2.34 s
2.35 s
9.3
9.76
9.65
9.2
1460
1480
1446,
1550
1465
3040
3050
8.61 d 7.52 7.78 m 5.28 d 3.47 d 0.81 t
2860,
2935,
2970
VIIb
8.72 d 7.34 7.83 m 5.31 d 3.39 d 0.79 t,
2.32 s
9.4
3235
3045
1460
1180,
1330
2855,
2940,
2970
a
1
For compounds VIa and VIb (OH) respectively 3480, 3520 and 3440 cm .
sulfonamides Va, b to afford N-(2-phenyl-2,2-di-
chloro-1-hydroxy- or 2-ethoxyethyl)arensulfonamides
(VIa, b, VIIa, b) and 1,1-di(arensulfonamido)-2-
phenyl-2,2-dichloroethanes IVa, b in high yields.
spectra of compound VIa from KBr pellets the ab-
sorption bands of N H and O H bonds appear as
1
double bands at 3190 and 3280, 3480 and 3520 cm
respectively. In solution in CCl4 the corresponding
spectrum contains single bands at 3370 (N H) and
1
3575 cm (O H). This absorption of the hydroxy
group suggests its participation both in hydrogen
bonds and intramolecular cyclization.
1
The H NMR spectra of compounds VIa, b, VIIa,
b contain signals of protons from groups NH, CH
with 3J(NH CH) 8 9 Hz, and multiplets from
1
protons in benzene rings (Table 2). In the H NMR
VI, VII, R = OH (VIa, b), OC2H5 (VIIa, b); Ar =
4-ClC6H4 (a), 4-CH3C6H4 (b).
spectra of compounds IVa, b due to coupling the
signal of NH proton is split into doublet, that of CH
into triplet; also appear the multiplets from benzene
ring protons.
Synthesized colorless crystalline compounds IV,
VI, VII are well soluble in acetone, dimethyl
sulfoxide, dimethylformamide, sparingly soluble in
chloroform, benzene, ethyl ether, insoluble in water.
Their composition and structure were proved by
EXPERIMENTAL
1
IR spectra were recorded on spectrophotometer
elemental analysis, H NMR and IR spectroscopy
1
UR-20 from KBr pellets in 400 4000 cm region.
(Tables 1, 2).
1H NMR spectra were registered on Jeol FX-90Q
instrument (90 MHz), solvent DMSO-, internal
reference HMDS.
In the IR spectra of compounds IVa, a, VIa, b,
VIIa, b appear the absorption bands of the stretching
and bending vibrations of the bonds N H, O=S=O,
and of benzene rings, alkyl and hydroxy groups
(Table 2). In the IR spectrum of compounds IVa, b
are observed two characteristic absorption bands of
N-(2-Benzene-2,2-dichloroethylidene)-4-chloro-
benzenesulfonamide (IIIa). To 5.12 g of compound
Ia dissolved in 15 ml of anhydrous carbon tetra-
chloride was slowly added dropwise at 15 20 C 9 ml
1
the N H bond at 3220 and 3280 cm . In the IR
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SYNTHESIS OF N-(2-BENZENE-2,2-DICHLOROETHYLIDENE)-4-...
287
of phenylacetylene (II) (at fast mixing of reagents
occurred self-heating to 55 60 C). Then the reaction
mixture was vigorously stirred at 55 60 C for
0.5 1 h. Throughout the reaction time nitrogen or
argon was bubbled through the reaction mixture. The
reaction mixture was cooled to 35 40 C, the
precipitated crystals were filtered off, washed with
hot petroleum ether, and extracted with hot benzene.
The compound insoluble in benzene was filtered off
to obtain 0.6 g (6%) of amide IVa. From the benzene
solution on cooling precipitated amide Va (1.9 g,
5%), mp 144 C (mp 143 145 C [5]). The mother
liquor in carbon tetrachloride was cooled, and the
precipitated compound was filtered off; thus we
obtained 5.9 g (82%) of imine IIIa.
from 3.4 g of imine (IIIb) and 1.7 g of amide Vb.
Yield of compound IVb 3.3 g.
N-(1-Hydroxy-2-phenyl-2,2-dichloroethyl)-4-
chlorobenzenesulfonamide (VIa). To a solution of
3.6 g of imine IIIa in 8 ml of chloroform was added
1 ml of water. The reaction mixture was stirred for
1 1.5 h at 35 C and then cooled to 5 10 C. The
crystalline reaction product was filtered off to obtain
3 g of compound VIa.
N-(1-Hydroxy-2-phenyl-2,2-dichloroethyl)-4-
methylbenzenesulfonamide (VIb) was obtained in
the same way from 3.4 g of imine IIIb. We separated
2.6 g of compound VIb.
N-(2-Phenyl-2, 2-dichloro-1-ethoxyethyl)-4-
chlorobenzenesulfonamide (VIIa) and -4-methyl-
benzenesulfonamide (VIIb) were obtained similarly
from 3.6 g of imine IIIa or 3.4 g of imine IIIb and
1 ml of ethanol. We isolated 3.2 g of compound VIIa
and 2.8 g of compound VIIb.
N-(2-Benzene-2,2-dichloroethylidene)-4-methyl-
benzenesulfonamide (IIIb) was prepared in a similar
way from 4.8 g of amide Ib and 9 ml of phenylacetyl-
ene (II). We obtained 5.4 g (80%) of imine IIIb,
0.6 g (8%) of compound IVb, and 0.2 g (7%) of
amide Vb, mp 138 C.
REFERENCES
1,1-Di(4-chlorophenylsulfonamido)-2-phenyl-2,2-
dichloroethane (IVa). To a solution of 3.6 g of
imine IIIa in 10 ml of benzene was added 1.9 g of
amide Va. The reaction mixture was refluxed in
benzene for 5 h at vigorous stirring, and then cooled
to room temperature. The precipitated crystals were
filtered off, washed with hot benzene and then with
ethyl ether. The compound that remained after
extraction with solvents was dried to yield 3.5 g of
amide IVa.
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Khim., 1992, vol. 28, no. 6, pp. 1236 1241.
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Zh. Org. Khim., 1985, vol. 21, no. 3, pp. 659 660.
3. Drozdova, T.I. and Mirskova, A.N., Zh. Org. Khim.,
1997, vol. 33, no. 10, pp. 1591 1592.
4. Drozdova, T.I. and Mirskova, A.N., Zh. Org. Khim.,
1998, vol. 34, no. 10, pp. 1519 1522.
5. Promyshlennye khlororganicheskie produkty (Industrial
Organochloro Compounds), Oshin, L.A., Ed.,
Moscow: Khimiya, 1978.
1,1-Di(4-methylphenylsulfonamido)-2-phenyl-
2,2-dichloroethane (IVb) was similarly prepared
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 37 No. 2 2001