A reaction of 2-diaminomethylidenedimedone with aryl isocyanates leads to the formation of the corresponding ureas, which upon the action of sodium methoxide cyclize to 4-amino-7,8-dihydroquinazoline-2,5(1H,6H)-dione derivatives. The latter react with aryl isocyanates following the similar scheme to furnish 1,6-diaryl-8,8-dimethyl-7,8-dihydro-1H-pyrimido-[4,5,6-de]quinazoline-2,5(3H,6H)-diones, new tricyclic compounds containing pyrimidopyrimidine fragment.
2-diaminomethidenedimedone 与芳基
异氰酸酯反应生成相应的
脲,在
甲醇钠的作用下环化成 4-
氨基-7,8-二氢
喹唑啉-2,5(1H,6H)-二酮衍
生物。后者与芳基
异氰酸酯发生类似的反应,生成 1,6-二芳基-8,8-二甲基-7,8-二氢-1H-
嘧啶并[4,5,6-de]
喹唑啉-2,5(3H,6H)-二酮,这是一种含有
嘧啶片段的新型
三环化合物。