Chemistry of kojic acid: One-step syntheses of benzothiazoles and other fused heterocycles from kojic acid derivatives

Abstract

The reactions of the benzyl ether (1b) of kojic acid (la) and its chloromethyl derivative (1c) were investigated as new routes to fused heterocyclic systems. The chloromethyl compound proved the more versatile intermediate yielding benzothiazoles with thiourea and pyrido[l,2-a]benzimidazoles (11) and pyrido[1,2-alindole (12b) with pyridine derivatives. A number of methylated products of the benzothiazole were prepared in order to establish the structures of the reaction products and a possible mechanism of the reaction is discussed.