Unusual intramolecular cyclization of adducts of diphenylacetylene with hetarenesulfenyl chlorides

Full text of DOI:10.1007/s11172-007-0336-1

Russian Chemical Bulletin, International Edition, Vol. 56, No. 10, pp. 2133—2134, October, 2007
2133
Unusual intramolecular cyclization of adducts
of diphenylacetylene with hetarenesulfenyl chlorides
V. K. Osmanov,a G. N. Borisova,a A. Geronikaki,b and A. V. Borisova
ꢀ
aR. E. Alekceev Nizhnii Novgorod State Technical University,
24 ul. Minina, 603606 Nizhnii Novgorod, Russian Federation.
Fax: +7 (831) 236 2311. Eꢀmail: ifxf@ nntu.nnov.ru
bAristotle University of Thessaloniki, Department of Pharmaceutical Chemistry,
University Campus, 54124 Thessaloniki, Greece.
Fax: 00 302310997612. Eꢀmail: geronik@pharm.auth.gr
Earlier, it was shown1—3 that products of 1,2ꢀaddition
of alkaneꢀ and arenesulfenyl chlorides at the multiple
bond of acetylenes, βꢀchlorovinyl sulfides, can undergo
the intramolecular nucleophilic substitution with the sulꢀ
fur atom in RS (R = Alk, Ar) fragment serving as the
nucleophile. Depending on the structural features of the
starting unsaturated compound, thiirenium salts or prodꢀ
ucts of their isomerization, thietene derivatives, are
formed.
densed heterocycles 4 and 5 in 73 and 87% yield, respecꢀ
tively (Scheme 2). The complete conversion of adduct 3а
requires 120 h, of adduct 3b, 96 h.
Scheme 2
In the present work, a reaction of diphenylacetylene
(1) with 3ꢀmethoxycarbonylpyridineꢀ2ꢀ and 1,3ꢀbenzoꢀ
thiazoleꢀ2ꢀsulfenyl chlorides (2а,b), containing potenꢀ
tially nucleophilic nitrogen atom in the hetaryl fragment,
was studied. We found that the reactions under considerꢀ
ation proceed in dichloromethane at 20 °C to form
βꢀchlorovinyl sulfides 3а and 3b in 95 and 92% yield,
respectively (Scheme 1).
Scheme 1
1H NMR spectra were recorded on a Bruker DRXꢀ500 specꢀ
trometer in DMSOꢀd6.
βꢀChlorovinyl sulfides 3а,b (general procedure). A solution of
sulfenyl chloride 2а,b (10 mmol) in dichloromethane (10 mL)
was added to a solution of diphenylacetylene (1) (1.78 g,
10 mmol) in dichloromethane (20 mL) at 20 °C. After 12 h, the
solvent was evaporated in vacuo to obtain compounds 3a,b, which
were recrystallized from hexane—dichloromethane.
Adducts 3а,b were found to be stable compounds both
under the reaction conditions and in the more polar media,
for example, in nitromethane with or without lithium
perchlorate, which were used earlier for the stimulation of
the intramolecular cyclization of βꢀchloroalkyl sulfides.4
The further transformations of compounds 3а,b take place
only upon treatment with such a strong Lewis acid as
SbCl5. The intramolecular cyclization of compounds 3а,b
proceeds in the presence of equimolar amount of SbCl5 in
dichloromethane at 20 °C with the ring closure by the
nitrogen atom of the HetS fragment to form the conꢀ
Methyl 2ꢀ[(E)ꢀ2ꢀchloroꢀ1,2ꢀdiphenylethenylsulfanyl]nicotinꢀ
ate (3a). The yield was 95%, gray crystals with m.p. 118—120 °C.
Found (%): C, 65.93; H, 4.17. C21H16ClNO2S. Calculated (%):
C, 66.05; H, 4.22. 1H NMR, δ: 3.95 (s, 3 H, OMe); 7.21 (dd,
3
1 H, Het, J = 4.7 Hz, 3J = 7.5 Hz); 7.30—7.60 (m, 10 H, Ph);
8.18 (d, 1 H, Het, 3J = 7.7 Hz); 8.38 (d, 1 H, Het, 3J = 5.0 Hz).
(E)ꢀ1ꢀ(1,3ꢀBenzothiazolꢀ2ꢀylsulfanyl)ꢀ2ꢀchloroꢀ1,2ꢀdipheꢀ
nylethene (3b). The yield was 92%, light yellow crystals with
m.p. 145—146 °C. Found (%): C, 66.21; H, 3.63. C21H14ClNS2.
1
Calculated (%): C, 66.39; H, 3.71. H NMR, δ: 7.30—7.55 (m,
10 H, 2 Ph); 7.40 (m, 2 H, Het); 8.10 (d, 1 H, Het, 3J = 8.1 Hz);
8.21 (d, 1 H, Het, 3J = 8.7 Hz).
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2061—2062, October, 2007.
1066ꢀ5285/07/5610ꢀ2133 © 2007 Springer Science+Business Media, Inc.

2134
Russ.Chem.Bull., Int.Ed., Vol. 56, No. 10, October, 2007
Osmanov et al.
Intramolecular heterocyclization of βꢀchlorovinyl sulfides 3a,b
(general procedure). A solution of SbCl5 (2.99 g, 10 mmol) in
dichloromethane (30 mL) was added to a solution of chloroꢀ
sulfide 3a,b (10 mmol) in dichloromethane (30 mL) at 20 °C
and this solution was kept at room temperature with monitoring
of its content every 12 h (1H NMR spectra were registered for
the residue after concentration of 0.5 mL of the solution). The
solution, containing only product 4 or 5, was concentrated, and
salts 4 or 5 were isolated from the residue by crystallization from
ether—dichloromethane.
C21H14Cl6NS2Sb. Calculated (%): C, 37.15; H, 2.08. 1H NMR,
3
δ: 6.78 (d, 1 H, Het, J = 8.5 Hz); 7.30—7.65 (m, 12 H, Ph,
Het); 8.43 (d, 1 H, Het, 3J = 8.3 Hz).
References
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Borisova, V. K. Osmanov, Zh. V. Matsulevich, N. G. Frolova,
and E. D. Savin, Khim. Geterotsikl. Soedin., 2005, 893 [Chem.
Heterocycl. Comp., 2005 (Engl. Transl.)].
8ꢀMethoxycarbonylꢀ2,3ꢀdiphenyl[1,3]thiazolo[3,2ꢀa]pyriꢀ
dinium hexachloroantimonate (4). The yield was 73%, yellow
crystals with m.p. 96—98 °C. Found (%): C, 36.92; H, 2.31.
C21H16Cl6NO2SSb. Calculated (%): C, 37.04; H, 2.37. 1H NMR,
δ: 4.10 (s, 3 H, OMe); 7.35—7.65 (m, 10 H, 2 Ph); 8.06 (dd,
3
3
3
1 H, Het, J = 6.5 Hz, J = 7.4 Hz); 8.92 (d, 1 H, Het, J =
6.5 Hz); 8.95 (d, 1 H, Het, 3J = 7.4 Hz).
2,3ꢀDiphenylbenzo[d][1,3]thiazolo[2,3ꢀb][1,3]thiazoliumꢀ4
hexachloroantimonate (5). The yield was 87%, yellow crystals
with m.p. 218—220 °C. Found (%): C, 37.03; H, 2.11.
Received June 29, 2007