4'-{[3-(2,4-dimethoxybenzyl)-6-ethyl-2,4-dioxo-3,4-dihydrothieno[2,3-d]pyrimidin-1(2H)-yl]methyl}biphenyl-2-carbonitrile   、                                                                                      
三氟乙酸                                                                                                                                                              在
                                                                                                                                                                                 
乙酸乙酯                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
甲苯                                                                                  为溶剂,
                                                                                                                                                    反应 2.0h,
                                                                                                                以to give the title compound as a colorless solid (46.1 g, 100%)的产率得到4'-[(6-ethyl-2,4-dioxo-3,4-dihydrothieno[2,3-d]pyrimidin-1(2H)-yl)methyl]biphenyl-2-carbonitrile