IMPROVED PROCESS FOR PREPARATION OF TRIAZOL-BENZODIAZEPINE DERIVATIVES

摘要

An improved process for preparation of triazol-benzodiazepine derivatives, such as alprazolam, triazolam, brotizolam and etizolam, is presented. The process comprises a cyclization reaction of compound Formula (B) in toluene with catalytic amount of ptoluene sulphonic acid to obtain the triazol-benzodiazepine derivative of Formula (C) wherein R is (D) and X is hydrogen or halogen.