Recyclization of 2-Iminochromenes via Ketene Aminal Intermediates: One-Pot, Three-Component Reaction for Synthesis of 1,4-Dihydropyridines-fused-1,3-diazaheterocycles
摘要:
An efficient, one-pot synthesis of 4-aryl-1,4-dihyropyrido[1,2-a]-fused-1,3-diazaheterocycles by three-component reaction of 1,n-diamine, nitroketene dithioacetal (1,1-di(methylthio)-2-nitroethene), and 2-iminochromenes in EtOH is reported. This new protocol has the advantages of good yields, short reaction times, and convenient operation. The structures were corroborated spectroscopically (infrared, H-1 and C-13 NMR, and electron impact-mass spectrometry) and by elemental analyses. A plausible mechanism for this type of recyclization is proposed. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications (R) to view the free supplemental file.
Synthesis of imidazo[1,2-a]pyridine, pyrido[1,2-a]pyrimidine, and 3-cyanocoumarin
作者:Mohammad Bayat、Monireh Rezaei
DOI:10.1007/s00706-017-2033-6
日期:2017.12
AbstractA one-pot protocol for the synthesis of tetrahydroimidazo[1,2-a]pyridines, tetrahydropyrido[1,2-a]pyrimidines, and 3-cyanocoumarine derivatives was developed by condensing of various 1,n-diamines, 1,1-bis(methylthio)-2-nitroethene, substituted salicylaldehyde, and malononitrile or alkyl cyanoacetate at reflux condition in ethanol. Graphical abstract
摘要通过缩合各种1,n-二胺,1,1-开发了一种一锅法合成四氢咪唑并[1,2- a ]吡啶,四氢吡啶并[1,2- a ]嘧啶和3-氰基香豆素衍生物的方法。双(甲硫基)-2-硝基乙烯,取代的水杨醛和丙二腈或氰基乙酸烷基酯在乙醇中回流的条件。 图形概要