indoloquinoxalines obtained by condensation of isatin with an unsymmetrical benzene-1,2-diamine, regioselective syntheses of the 1-, 2-, 3-, and 4-aminoindolo[2,3-b]quinoxalines have been developed. With the four derivatives in hand, isomers obtained by direct cyclocondensations starting from amino or nitro substituted benzene-1,2-diamines could be unambiguously identified. The results of these studies show
鉴于文献中发表的关于通过
靛红与不对称苯-1,2-二胺缩合获得的
吲哚并
喹喔啉结构的矛盾结果,1-、2-、3-和
4-氨基吲哚的区域选择性合成[已开发出2,3-b]
喹喔啉。有了这四种衍
生物,就可以明确地鉴定从
氨基或硝基取代的苯-1,2-二胺开始直接缩合获得的异构体。这些研究的结果表明,一方面,一些先前的发现需要修改,另一方面,1-
氨基异构体可以一步制备,产率为 58%。