对苯二甲醛   、                                                                                      
6-<<(dimethylamino)methylene>amino>-1,3-dimethyluracil   、                                                                                      
邻甲苯胺                                                                                                                                                                                              以
                                                                                         
甲苯                                                                                  为溶剂,
                                                                                                                                                                                        以78%的产率得到5,6-dihydro-5-(4-(1,2,3,4,5,6-hexahydro-1,3-dimethyl-2,4-dioxo-6-o-tolylpyrimido[4,5-d]pyrimidin-5-yl)phenyl)-1,3-dimethyl-6-o-tolylpyrimido-[4,5-d]pyrimidine-2,4-(1H,3H)-dione