Hydrotalcite: A novel and reusable solid catalyst for one-pot synthesis of 3,4-dihydropyrimidinones and mechanistic study under solvent free conditions

Synthesis of 3,4-dihydropyrimidinones/thiones, a multicomponent synthesis using ethyl acetoacetate, substituted aromatic aldehydes, and urea/thiourea has been carried out in presence of Mg–Al–CO3 and Ca–Al–CO3 hydrotalcite as a reusable solid catalyst. The work has been carried out under thermal solvent-free conditions without microwave irradiations, and under microwave irradiation. In this method excellent yield of 3,4-dihydropyrimidinones/thiones is reported in shorter duration. Hydrotalcites are non-toxic, easy to separate and recyclable catalyst hence making this process environment friendly. Mechanistic study of the reaction using hydrotalcites as catalyst has been studied under thermal conditions without microwave irradiations.

. Synthesis of 3,4-dihydropyrimidinones/thiones by cyclocondensation of ethyl acetoacetate, substituted aromatic aldehydes, and urea/thiourea using Mg–Al–CO3 and Ca–Al–CO3 hydrotalcites as a reusable catalyst has been reported under solvent-free conditions and microwave irradiations.Figure optionsDownload high-quality image (107 K)Download as PowerPoint slideHighlights
► This catalytic reaction takes place under solvent free conditions thus eliminating organic solvent, it gains an environment friendly condition.
► Yield of the desired product is excellent in the present synthesis.
► Hydrotalcite is a reusable heterogeneous catalyst there is no significant loss of catalytic activity when tested up to five catalytic cycles.
► Hydrotalcite catalyst containing Mg, Al and Ca are environment friendly metals.