Environmentally Friendly and Facile Synthesis of 2-oxo- and Thioxo-1,2,3,4-tetrahydropyrimidines Catalyzed by Formic Acid as a Natural Green and Bio-based Catalyst under Solvent-Free Conditions

Abstract

A green synthetic route to the facile Biginelli synthesis of 2-oxo- and thioxo-1,2,3,4-tetrahydropyrimidines have been developed using formic acid as a natural green and bio-based catalyst under solvent-free reaction conditions. All reactions are completed in a short period of times and the products are obtained in high to excellent yields. The salient features of this green approach are simple work-up with no necessity of chromatographic purification steps, absence of hazardous organic solvents, use of safe, non-volatile, noncorrosive and readily green catalyst, solvent-free conditions, one-pot reaction, ecofriendly and clean synthesis.