1-<(4-Methoxyphenyl)methylthio>-2,5-pyrrolidindion   、                                                                                      
diethyl 1,4-dimethyl-3,6-dioxopiperazine-2,5-dicarboxylate                                                                                                                                                              在
                                                                                                                                                                                 hydroquinindine-2,5-diphenyl-4,6-pyrimidinediyl diether                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
甲苯                                                                                  为溶剂,
                                                                                                                                                                                        以80%的产率得到Diethyl trans-2,5-bis(4-methoxybenzylsulfanyl)-1,4-dimethyl-3,6-dioxopiperazine-2,5-carboxylate