Oxalic acid as a versatile catalyst for one pot facile synthesis of 3,4-dihydropyrimidin-2-(1<i>H</i>)-ones and their thione analogues
作者:Jaiprakash N. Sangshetti、Devanand B. Shinde、Nagnnath D. Kokare
DOI:10.1002/jhet.5570450440
日期:2008.7
3,4-Dihydropyrimidin-2-(1H)-ones and their thioneanalogues are synthesized from the condensation of aromatic aldehydes, β-dicarbonyl compound and urea or thiourea in presence of 5 mol% of oxalicacid in ethanol-water (1:2; v/v) under mild reaction conditions. The yields obtained are better and also the use of very inexpensive catalyst, environmentally benign solvent and easy work-up are the advantageous
3,4-二氢嘧啶-2-(1 H)-及其硫酮类似物是由芳香醛,β-二羰基化合物与脲或硫脲在乙醇水溶液中存在5 mol%的草酸缩合而成的(1 :2; v / v)在温和的反应条件下。获得的产率更好,并且使用非常便宜的催化剂,对环境无害的溶剂和易于后处理是本方法的有利方面。