The reactive 1:1 zwitterionic intermediate formed by the addition of isocyanides to dialkyl acetylenedicarboxylates was trapped by 3,6-dihydroxypyridazine to produce 3-amino-5,8-dioxo-5,8-dihydro-1 H-pyrazolo[1,2- A]pyridazines in good yields.
通过将异
氰化物添加到
乙炔二
羧酸二烷基酯中形成的反应性 1:1 两性离子中间体被 3,6-二羟基
哒嗪捕获,生成 3-amino-5,8-dioxo-5,8-dihydro-1 H-pyrazolo[1,2 - A]
哒嗪类化合物的收率很高。