Copper-Catalyzed One-Pot, Three-Component Synthesis of Imidazo[1,2-c]quinazolines and Benzimidazo[1,2-c]quinazolines

Abstract

A highly efficient copper-catalyzed three component, one-pot reaction has been described for the synthesis of imidazo[1,2-c]quinazolines and benzimidozo[1,2-c]quinazolines from 2-(2-bromophenyl)-1H-imidazoles/benzimidazoles using benzyl alcohol or benzylamine as benzaldehyde surrogate and sodium azide as nitrogen source. Various functional groups were well tolerated and desired products were obtained in moderate to good yields. The reaction involves copper-catalyzed sequential azidation of 2-(2-bromophenyl)-1H-imidazoles/benzimidazoles through SNAr reaction and reductive amination followed by oxidative condensation with benzyl alcohols or benzylamines. The significant practical advantages of the protocol are utilization of the readily accessible simple substrates, broad substrate scope, and ligand-free reaction conditions.