Collect. Czech. Chem. Commun. 1988, 53, 311-318

Vilsmeier-Haack reaction of 2-amino-X-benzothiazoles with N-phenylformamide in the presence of benzenesulfonyl chloride

Margita Lácová, Nguyen Thi Nga and Ján Halgaš

Department of Organic Chemistry Comenius University, 842 15 Bratislava


2-Amino-X-benzothiazoles (X = H, 4-Cl, 6-Cl, 6-NO2, 6-CH3, 6-OCH3, 6-Br) react with N-phenylformamide and two equivalents of benzenesulfonyl chloride in pyridine, affording different products in dependence on the substituent X: N-(X-2-benzothiazolyl)formamidines, N-phenyl-N’-(X-2-benzothiazolyl)formamidines, N-phenyl-N’,N’’-bis(X-2-benzothiazolyl)triaminomethanes, N-(X-2-benzothiazolyl)benzenesulfonamides and N-2-((X-3-phenyliminomethyl)-benzothiazolylidene)benzenesulfonamides. In the presence of one equivalent of benzenesulfonyl chloride, benzothiazoles I either do not react or are partially benzenesulfonated.