Derivatives of Thiazolo [3, 2-α] benzimidazole (Studies on Heterocyclic Compounds. II)

Abstract

Depending upon reaction conditions, 2-mercaptobenzimidazole (I) treated with α-chloroacetaldehyde dimethylacetal under acidic or with ethylene dichloride under alkaline conditions undergo cyclization (V and VIII). Thioethers (IX and XI) are treated with acetic anhydride in pyridine to yield 2-alkyl-3-oxothiazolidino [3, 2-α] benzimidazoles (X) and p-substituted 3-phenylthiazolo [3, 2-α] benzimidazoles (XII).