[EN] IMPROVED PROCESS FOR PREPARATION OF TRIAZOL-BENZODIAZEPINE DERIVATIVES<br/>[FR] PROCÉDÉ AMÉLIORÉ DESTINÉ À LA PRÉPARATION DE DÉRIVÉS DE TRIAZOL-BENZODIAZÉPINE
                        
                            
                                申请人:CENTAUR CHEMICALS PVT LTD
                            
                            
                                公开号:WO2009069147A2
                            
                            
                                公开(公告)日:2009-06-04
                            
                            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.