描述:
E-7-<(1,2-bis(methoxycarbonyl)ethylidene)hydrazino>-1,3-dimethyl-2,4(1H,3H)-dioxopyrido<2,3-d>pyrimidine 在
PPA 、 Polyphosphoric acid (PPA) 作用下,
反应 2.0h,
以57.6%的产率得到7-(5-hydroxy-3-methoxycarbonyl-1-pyrazolyl)-1,3-dimethyl-2,4(1H,3H)-dioxopyrido<2,3-d>pyrimidine