One-pot Four Component Reaction of Unsymmetrical 1-Methylbarbituric Acid with BrCN and Various Aldehydes in the Presence of Et<sub>3</sub>N and/or Pyridine
作者:Mohammad Jalilzadeh、Nader Noroozi Pesyan
DOI:10.5012/jkcs.2011.55.6.940
日期:2011.12.20
which are dimeric forms of 1-methyl barbiturate at the range of 0 o C to room temperature. In the reaction of some aldehydes with 1-MBA and BrCN were afforded a mixture of diastereomers. Another two aldehydes such as 4-cyano- and 2-hydroxybenzaldehydes gave exclusively two diastereomers in which binded to the salt of triethylammonium hydrobromide by intermolecular H-bond in ratio of 1:1. 4-Hydroxybenzaldehyde
1-甲基嘧啶-(1H,3H,5H)-2,4,6-三酮(1-MBA 1)作为不对称巴比妥酸与溴化氰和各种醛的反应在三乙胺和/或吡啶的存在下提供非对映异构体混合物类杂环稳定的5-芳基-1,1'-二甲基-和5-芳基-3,1'-二甲基-1H,1'H-螺(呋喃(2,3-d)嘧啶-6,5 '-嘧啶)2,2',4,4',6'(3H,3'H,5H)-戊酮,它们是在0℃至室温下巴比妥酸1-甲酯的二聚体形式。在一些醛与1-MBA和BrCN的反应中,得到非对映异构体的混合物。另外两个醛,例如4-氰基和2-羟基苯甲醛,仅产生两个非对映异构体,其中两个非对映异构体通过分子间氢键以1:1的比例结合到氢溴酸三乙铵的盐上。在相同条件下,4-羟基苯甲醛和2-吡啶-甲醛仅产生一种非对映异构体。具有强电子给体的醛仅由Knoevenagel加合物的两个几何异构体(E和Z异构体)生产。通过1 H NMR,13 C NMR和FT-I