9-[1-(4-Chloro-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89%的产率得到(6S,9S)-9-Bromo-9-[bromo-(4-chloro-phenyl)-methyl]-6-methyl-4-oxo-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidine-3-carboxylic acid ethyl ester