| 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 p-toluene sulphonic acid to obtain the triazol-benzodiazepine derivative of Formula C: wherein R is, and X is hydrogen or halogen. |
