ChemInform Abstract: Microwave‐Assisted Cadogan Reaction for the Synthesis of 2‐Aryl‐2H‐indazoles, 2‐Aryl‐1H‐benzimidazoles, 2‐Carbonylindoles, Carbazole, and Phenazine.

Abstract

Microwave-Assisted Cadogan Reaction for the Synthesis of 2-Aryl-2H-indazoles, 2-Aryl-1H-benzimidazoles, 2-Carbonylindoles, Carbazole, and Phenazine. -The Cadogan reaction is modified by using microwave irradiation as the source of heat instead of conventional heating. Appropriate starting materials are mixed with triethyl phosphite or triphenylphosphine and irradiated for several minutes at a specific power to provide the title products. The microwave-assisted Cadogan reaction greatly enhances the yields of the products and reduces the reaction time essentially. In the case of decomposition during the procedure, triphenylphosphine is shown to be an alternative, because the reaction can be performed at lower power and still gives good yields.