4-Dihydropyrimidin-2(1H)-one derivatives were synthesized using layered α-zirconium sulfophenylphosphonate as a recyclableheterogeneouscatalyst. Several classes of reagents, such as functionalized aromatic and aliphatic aldehydes, β-dicarbonyl derivatives and 2-aminobenzimidazole, were used to synthesize different 3,4-dihydropyrimidin-2(1H)-one derivativesundersolventfree conditions.Graphical Abstract
Ion exchange resin catalyzed multicomponent Biginelli reaction is studied for the synthesis of 3,4- dihydropyrimidin-2-ones. Among the various solid acid catalysts Indion-130 was found to be most efficient, recyclable and environmentally benign heterogeneous catalyst regarding reaction time, yield and ease of work up procedure.
Synthesis of Biginelli Compounds Using Cobalt Hydrogen Sulfate
作者:Hamid Reza Memarian、Mahnaz Ranjbar
DOI:10.1002/jccs.201190016
日期:2011.8
Efficient synthesis of various 2‐oxo(thioxo)‐1,2,3,4‐tetrahydropyrimidines containing acetyl, carboethoxy, carbomethoxy and carboxamide groups on 5‐position of the N1‐substituted and N1‐unsubstituted heterocyclic ring was achieved using cobalt hydrogen sulfate Co(HSO4)2 under thermal conditions. Good to high yield, shorter reaction times, easy work up and simple preparation of Co(HSO4)2 are the advantages
The reaction of aldehydes, β-dicarbonyl compounds and urea (Biginelli reaction) has been performed over solid acid catalysis, undersolventlessconditions or in water affording dihydropyrimidines in good yield and selectivity.
An effective one-pot synthesis of dihydropyrimidinonoes using Melamine-formaldehyde resin supported H+ (MFRH) as an inexpensive and readily available reagent through Biginelli condensation reaction of aldehyde, 1,3-dicarbonyl compounds and (thio)urea in conventional and under microwave irradiation conditions is described. Excellent yields, short reaction times for formation of the products and simple work-up are attractive features of this green protocol.