Electrosynthesis of sulfur-containing compounds from vinyl sulfones having a cyano group was studied using a reactive sulfur-graphite electrode, 3-Aryl-2-phenylsulfonylpropenenitriles (la-c) and 2-phenyl-3-phenylsulfonylpropenenitrile (Id) were used as vinyl sulfones. In acetonitrile, la-c having geminal cyano and sulfonyl groups gave dimeric 5-arylisothiazoles bridged with two or three sulfur atoms at the 3-position in moderate yields. Similarly, Id having vicinal cyano and sulfonyl groups yielded dimeric 4-phenylisothiazole bridged with two sulfur atoms together with 3-[(Z)-2-cyano-2-phenylethenylthio]-5-phenylisothiazole. In N,N-dimethylformamide products which involve the solvent were not obtained and the result was almost the same as those in acetonitrile. This electrosynthesis of sulfur-containing compounds is characterized as elimination of a phenylsulfonyl group accompanying the addition of polysulfide anion(s) produced by electroreduction of elemental sulfur. (C) 1999 Elsevier Science B.V. All rights reserved.