On reacting the 3-aminopyridazines 1a,d,e with dimethyl acetylenedicarboxylate (DMAD), the pyrimido[1,2-b]pyridazin-2-(2H)-ones 2e-g, whereas starting from 1f, the 4(4H)-ones 5a and 3b,d were prepared. In the 2(2H)-one series, the reactions of 2b with various amino compounds resulted in various types of products. The reaction of N-methylaminopyridazines 1g,h with DMAD led to the endo-N-substituted
3-
氨基
哒嗪1a,d,e与
乙炔二
甲酸二甲酯(
DMAD)反应后,
嘧啶并[1,2 - b ]
哒嗪-2-(2 H)-ones 2e-g,而从1f开始,4(4制备了H 5 -one 5a和3b,d。在2(2 H)-one系列中,2b与各种
氨基化合物的反应生成各种类型的产物。N-甲基
氨基
哒嗪1g,h与
DMAD的反应生成了N-取代的内衍
生物8a,b,而1h用
乙氧基亚甲基丙二酸二乙酯(D
EM)制得外-N-取代的化合物1k。化合物的组成已通过光谱和
化学证据证明。