这项工作提出了在硝酸铈铵(CAN)存在下通过芳族醛,β-酮酸酯的直接缩合在微波辅助下无溶剂合成N,N'-二烷基-4-芳基-3,4-二氢嘧啶酮/硫酮的方法,以及N,N'-二烷基脲/硫脲。所采用方法的重点是:(i)反应物易于缩合为无任何副产物的产物;(ii)反应时间短,产率高,纯度高。所有合成的化合物都通过光谱技术(例如FTIR,1 H NMR,13 C NMR和Mass)进行了表征和建立。该化合物的结构通过单晶X射线衍射分析得到了进一步证实。
A general, efficient and green method for the synthesis of dihydropyrimidinones is described under mild conditions employing low melting mixtures of L-(+)-tartaric acid and urea derivatives as a novel reaction medium. The melt plays a triple role: as solvent, as catalyst and as reactant, furnishing highly functionalized dihydropyrimidinones in good to excellent yields.
Dowex-promoted general synthesis of N,N′-disubstituted-4-aryl-3,4-dihydropyrimidinones using a solvent-free Biginelli condensation protocol
作者:Kamaljit Singh、Divya Arora、Sukhdeep Singh
DOI:10.1016/j.tetlet.2006.04.061
日期:2006.6
Dowex-50W ion exchange resin-promoted solvent-free heating of an intimate mixture of an aldehyde, an active methylene compound and N,N'-dimethylurea furnished the title compounds in moderate to good yields. (c) 2006 Elsevier Ltd. All rights reserved.