Efficient Cu‐catalyzed Synthesis of Benzimidazoles Using Ammonia as Nitrogen Source in Water

Abstract In present work, we have developed an efficient strategy for the synthesis of 2‐substituted benzimidazoles via Cu‐catalyzed Ullmann condensation reaction of o ‐halobenzanilides with ammonia in water. This protocol is applicable to a wide variety of 2‐substituted benzimidazoles bearing functional groups tolerance, which features one‐pot, high yields, functional groups tolerable and green solvent.