Formation of polyheterocyclic systems by reaction of 2-imino-4-methyl-2H-1-benzopyran-3-carbonitrile with active methylene compounds
作者:Conor N. O'Callaghan、T. Brain H. McMurry、John E. O'Brien、Sylvia M. Draper、Deborah J. Wilcock
DOI:10.1039/p19960001067
日期:——
2-Imino-4-methyl-2H-1-benzopyran-3-carbonitrile undergoes [1,5] tautomerism in solution to 2-amino-4-methylidene-4H-1-benzopyran-3-carbonitrile. Reaction with one equivalent of compounds containing a reactive methylene group affords simple 4-methylbenzopyran derivatives, and a methylidene derivative (of [1]benzopyrano[2,3-b][1,8]naphthyridine). Reaction with two and three equivalents of malononitrile affords derivatives of [1]benzopyrano[2,3,4-de]quinoline and [1]benzopyrano[2,3,4-de][1,6]-naphthyridine, which had previously been formulated as bicyclic benzopyran derivatives. The X-ray crystal structure of ethyl 3-amino-2-cyano-3-(2-imino-4-methyl-2H-1-benzopyran-3-yl)prop-2-enoate has been determined, showing the presence of two molecules in the asymmetric unit.
2-亚氨基-4-甲基-2H-1-苯并吡喃-3-甲腈在溶液中发生[1,5]互变异构,生成2-氨基-4-亚甲基-4H-1-苯并吡喃-3-甲腈。与一当量含有活性亚甲基的化合物反应,得到简单的4-甲基苯并吡喃衍生物和亚甲基衍生物([1]苯并吡喃并[2,3-b][1,8]萘啶)。与两当量和三当量的丙二腈反应,得到[1]苯并吡喃并[2,3,4-去]喹啉和[1]苯并吡喃并[2,3,4-去][1,6]-萘啶的衍生物,其先前已被配制为双环苯并吡喃衍生物。 3-氨基-2-氰基-3-(2-亚氨基-4-甲基-2H-1-苯并吡喃-3-基)丙-2-烯酸乙酯的X射线晶体结构已确定,表明存在不对称单元中的两个分子。