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

摘要

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 ~(13)CNMR, while four of them (3o, 3w, 4 and 5) have also been characterized by single crystal X-ray analysis.