9-[1-(4-Methoxy-phenyl)-meth-(E)-ylidene]-6-methyl-4-oxo-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidine-3-carboxylic acid ethyl ester 在
溴 作用下,
以
二氯甲烷 为溶剂,
反应 3.0h,
以82%的产率得到(6S,9S)-9-Bromo-9-[bromo-(4-methoxy-phenyl)-methyl]-6-methyl-4-oxo-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidine-3-carboxylic acid ethyl ester