Copper-catalyzed synthesis of 2-aminobenzimidazoles from carbonimidoyl dichlorides and amines

A new protocol for the synthesis of a variety of 2-aminobenzimidazole derivatives has been developed. O-haloaryl carbonimidoyl dichloride reacted with anilines to generate an o-haloaryl guanidine intermediate, which underwent copper catalyzed ring closure to afford 2-aminobenzimidazole derivative in moderate yields