Facile synthesis of 1,3,4-benzotriazepines and 1-arylamide-1H-indazoles via palladium-catalyzed cyclization of aryl isocyanates and aryl hydrazones under microwave irradiation

Abstract

A strategy involving palladium-catalyzed cyclization of halo-phenyl hydrazones and aryl isocyanates provides a convenient approach to the synthesis of 1,3,4-benzotriazepines (4) or 1-arylamide-1H-indazoles (5) in good isolated yields. Microwave irradiation was found to afford high reaction efficiency, while the choice of halophenyl hydrazone had an effect on the pathway of the reaction.