Unusual difluoromethylation of 2-mercaptoazoles

The conditions for difluoromethylation of 2-mercaptobenzimidazoles with dif luorocarbene (CHClF2 in alkaline medium) at the sulfur atom or at two react ion centres - sulfur and nitrogen or two nitrogen atoms - were found. In th e similar reaction, 2-mercapto-4(5)-(4-nitrophenyl)imidazole gives the prod uct of bis(difluoromethylation) at the sulfur and nitrogen atoms. Benzimida zoles with two fluorinated alkyl substituents at the two nitrogen atoms wer e prepared for the first time. The N-difluoromethyl derivative of benzothia zole-2-thione was obtained by this procedure. (C) 2001 Elsevier Science B.V . All rights reserved.