Synthesis of fused ring heterocycles from aromatic amines with hydroximoyl chlorides

Abstract

Abstract Substituted 2‐arylbenzimidazoles, 2‐arylbenzoxazoles and 2‐arylbenzothiazoles were obtained in good yield by the reaction of hydroximoyl chlorides with ortho ‐substituted aromatic amines. The benzo moiety of the benzimidazoles was shown by nmr to be symmetrical, indicating that the N‐H group proton of the imidazole ring is exchanging with the water protons in the DMSO‐d 6 solvent.