2-氨基-1H-咪唑-5-羧酸乙酯   、                                                                                      
tert-butyl 2-(2,4-dichlorobenzylidene)-3-oxobutanoate                                                                                                                                                                                              以
                                                                                         
乙醇                                                                                  为溶剂,
                                                                                                                                                    反应 16.0h,
                                                                                                                以to obtain a 10:1 mixture (by HPLC) of 6-tert-butyl 2-ethyl 5-(2,4-dichlorophenyl)-7-methyl-5,8-dihydroimidazo[1,2-a]pyrimidine-2,6-dicarboxylate and 6-tert-butyl 3-ethyl 5-(2,4-dichlorophenyl)-7-methyl-5,8-dihydroimidazo[1,2-a]pyrimidine-3,6-dicarboxylate (3.07 g, 100% crude yield) as a yellow foam的产率得到6-tert-butyl 2-ethyl 5-(2,4-dichlorophenyl)-7-methyl-5,8-dihydroimidazo[1,2-a]pyrimidine-2,6-dicarboxylate