Reactions of benzo-1,2,3-dithiazolium salts and their selenium analogs with amines

The corresponding 6-arylamino derivatives were obtained by reaction of 6-chloro, 6-bromo, and 6-methoxy derivatives of benzo-1,2,3-dithiazolium and their selenium analogs — benzo-1,2,3-thiaselenazolium, benzo-2,1,3-thiaselenazolium, and benzo-1,2,3-diselenazolium salts — with aromatic amines. The 6-methoxy derivatives also react with acetates of secondary aliphatic amines, whereas in the case of the chloro derivatives attack is directed to the heteroring. 6-Aryl(dialkyl)amino derivatives of dithiazolium and 1,2,3-thiaselenazolium salts are protonated in concentrated sulfuric acid at the exocyclic nitrogen atom. The analogous derivatives of 2,1,3-thiaselenazolium and diselenazolium salts under the same conditions form a tautomeric mixture of dications, the position of the equilibrium between which depends on the substituent. The electronic and PMR spectra of the amination products are presented.