INTERMEDIATES FOR THE SYNTHESIS OF BENZIMIDAZOLE COMPOUNDS AND PROCESS FOR THE PREPARATION THEREOF.

摘要

Problem: To provide intermediates for the synthesis of benzimidazole compounds having an excellent antihyperglycemic activity or salts thereof and a process for the preparation thereof. Means for solutions: A process for the preparation of benzimidazole compounds (I), characterized by condensing an amine derivative (III) with a carboxylic acid derivative (II) to form a compound (IV) and subjecting the compound (IV) to ring closure in the presence of an acid (wherein R1 is C1-C6alkyl, C1-C6alkoxy, or the like; R2 is C1-C6alkyl; and R3 is hydrogen or a protective group).