1-Aryl-4-aroyl-5-(methoxycarbonyl)-1Н-pyrrole-2,3-diones react with methyl 4-aryl-2-(arylamino)-4-oxobut-2-enoates with the formation of methyl 1,7-diaryl-4,9-diaroyl-3-hydroxy-2,6-dioxo-1,7-diazaspiro[4.4]nona-3,8-diene-8-carboxylates.
1-芳基-4-芳酰基-5-(甲氧基羰基)-1--
吡咯-2,3-二酮与4-芳基-2-(芳基
氨基)-4-氧代丁-2-烯酸甲酯反应形成甲基1 ,7,7-二芳基-4,9-二芳基-3-羟基-2,6-二氧代-1,7-二氮杂螺[4.4]壬娜-3,8-二烯-8-
羧酸盐。