酮醇-S,S-乙缩醛(5a–c)在醇性钠的醇盐存在下与胍和硫脲反应,得到2-氨基和2-巯基-4-烷氧基-5-芳基-6-甲基-吡啶二酰亚胺(6a–k)分别以良好的收成。α-氰基碳烯-S,S-乙缩醛(9a–d)同样产生了带有胍的5-取代的2,4-二氨基-6-烷氧基-吡啶亚胺(10a-e),总收率为50-60%。未交换的2,4-二氨基-5- p -氯苯基-6-甲硫基嘧啶(11)制备图9c为使用用于描述identifical条件的典型例子7。5,6-稠合嘧啶的合成(14a–f),(19)和(23a–e)也使用环状乙烯酮-S,S-缩醛(13a–c)和(22a–b)完成。发现本方法比报道的烷氧基和甲硫基嘧啶的方法更方便和有效。
A water-mediated regioselective synthesis of 6,7-diaryl-5-oxo-2,3,5,6-tetrahydroimidazo[1,2-a]pyridine-6-carbonitriles was performed by the reaction of 2-[1-cyano-2,2-bis(methylsulfanyl)vinyl]benzonitrile with 1-aryl-2-(imidazolidin-2-ylidene)ethanones under basic conditions. This reaction involves an unprecedented (4+2) annulation.