An Unprecedented Synthesis of N-Phenyl Amides via Cleavage of Benzotriazole Ring under Free Radical Condition

Abstract

An attempt of Bu3SnH mediated cyclization of acylbenzotriazoles (RCOBt) to corresponding benzoxazole failed; instead, corresponding N-phenylamides were achieved in good yield. The reactions proceed via reductive cleavage of benzotriazole ring with consequent evolution of molecular nitrogen (N2). A diverse range of amide has been achieved in high yields. Structures of all the compounds have been elucidated using IR, MS, 1H and 13C NMR, while four of them (3 o, 3 w, 4 and 5) have also been characterized by single crystal X-ray analysis. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim