4-Sulfobenzoic Acid as an Efficient Catalyst for the Preparation of 3,4-dihydropyrimidin-2-(1H)-ones Under Solvent-free Conditions

Document Type: Research Paper


Department of Chemistry, Faculty of Science, University of Sistan and Baluchestan, Zahedan, Iran


In this research, one-pot three-component synthesis of 3,4-dihydropyrimidin-2-(1H)-ones have
been developed using Biginelli reaction from the interaction between ethyl/methyl acetoacetate,
aromatic aldehydes, and urea/thiourea in the presence of 4-sulfobenzoic acid as a new, effective,
inexpensive, and available bronsted acid. Avoidance of toxic and dangerous solvents, easy isolation
of products without the need of column chromatography, high yields, and short reaction time are
some important features of the present method.