Answers are grounded in this paper and cite their sources.
A green and efficient method for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones and -thiones through one-pot three-component reaction of ethyl acetoacetate, an aryl aldehyde, and urea or thiourea in acetonitrile using silica gel-supported polyphosphoric acid (PPA- SiO₂ ) as catalyst is described. Compared to the classical Biginelli reaction conditions, the present methodology offers several advantages such as high yields, relatively short reaction times, mild reaction condition and a recyclable catalyst with a very easy work up.
No takes yet. Share an insight, caveat, or question.
Zeinali‐Dastmalbaf et al. (2011) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: