(E)-2-[N'-Methyl-N'-(1-methyl-2-methylsulfanyl-6-oxo-1,6-dihydro-pyrimidin-4-yl)-hydrazino]-but-2-enedioic acid dimethyl ester                                                                                                                                                              在
                                                                                                                                                                                 PPA   、                                                                                                  Polyphosphoric acid (PPA)                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
甲苯                                                                                  为溶剂,
                                                                                                                                                    反应 0.5h,
                                                                                                                以92%的产率得到1,7-Dimethyl-8-methylsulfanyl-5,6-dioxo-4,5,6,7-tetrahydro-1H-pyrimido[4,5-c][1,2]diazepine-3-carboxylic acid methyl ester