Vulnerability of substituted aromatic hydroxy aldehydes to undergo Biginelli reaction in water

Abstract

Aromatic aldehydes having hydroxyl substituent(s) react with urea (or thiourea), and ethyl acetoacetate (or acetylacetone) in the presence of p-toluenesulfonic acid as catalyst and water as solvent to give substituted dihydropyrimidinones (Biginelli compounds) in good to excellent yields.