反应详情

A solution of 22.0 g of 7-chloro-5-(2-fluorophenyl)-2-methylthio-3H-1,4-benzodiazepine and 20.0 g of L-threonine methyl ester hydrochloride in 200 ml of pyridine was stirred at 75° C. for 5 h. The solvent was removed in a vacuum and the residue was purified by chromatography on 800 g of silica gel with dichloromethane containing 5% methanol. There were obtained 16.3 g (59%) of methyl 2-[7-chloro-5-(2-fluorophenyl)-3H-1,4-benzodiazepin-2-ylamino]-3-hydroxy-butyrate as a diastereomer mixture which was used without further purification as the starting product for the step described below.

1. customThe solvent was removed in a vacuum
2. customthe residue was purified by chromatography on 800 g of silica gel with dichloromethane containing 5% methanol