The reactions of enaminones (6-aminouracils) 1a–c and 4 with cyano olefins 2a–b and 5a–f led to the formation of pyrido[2,3-d]pyrimidines 3a–f and 6a–f in good yield, while the treatment of 4-amino-2-thiouracil 4 with aromatic aldehydes afforded pyridodipyrimidines 7a–c.
烯胺酮(6-
氨基尿
嘧啶)1a – c和4与
氰基烯烃2a – b和5a – f的反应导致
吡啶[2,3- d ]
嘧啶3a – f和6a – f的高收率形成,而用芳族醛处理4-
氨基-2-
硫尿
嘧啶4得到
吡啶二
嘧啶7a – c。