(R)-7-[3-tertbutoxycarbonylamino-4-(2,4,5-tri-fluorophenyl)butyryl]-3-trifluoromethyl-5,6,7,8-tetrahydro-imidazo[1,5-a]pyrazine-1-carboxylic acid 、
乙醇 、
三乙胺 、
双(2-氧代-3-恶唑烷基)次磷酰氯 在
silica gel 、
(R)-7-[3-tert-butoxycarbonylamino-4-(2,4,5-trifluoro-phenyl)-butyryl]-3-trifluoromethyl-5,6,7,8-tetrahydro-imidazo[1,5-a]pyrazine-1-carboxylic acid ethyl ester 作用下,
以
二氯甲烷 为溶剂,
反应 5.0h,
以to obtain the title compound (R)-7-[3-tert-butoxycarbonylamino-4-(2,4,5-trifluoro-phenyl)-butyryl]-3-trifluoromethyl-5,6,7,8-tetrahydro-imidazo[1,5-a]pyrazine-1-carboxylic acid ethyl ester 23a (0.1 g) as a colourness oil的产率得到(R)-7-[3-tert-butoxycarbonylamino-4-(2,4,5-trifluoro-phenyl)-butyryl]-3-trifluoromethyl-5,6,7,8-tetrahydro-imidazo[1,5-a]pyrazine-1-carboxylic acid ethyl ester