Chromium (III) Nitrate Nonahydrate: An Environmentally Benign and Efficient Heterogeneous Catalyst for Facile One-Pot Biginelli Synthesis of 3,4-Dihydropyrimidin-2-(1H)-One/Thione Derivatives Under Solvent-Free Conditions

摘要

The use of chromium(III) nitrate nonahydrate (Cr(NO3)3·9H2O) as an efficient, mild and economical catalyst for the one-pot three-component Biginelli synthesis of 3,4-dihydropyrimidin-2-(1H)-one/thione derivatives in the reaction between β-keto esters (methyl or ethyl acetoacetate), aromatic aldehydes (benzaldehye derivatives) and urea or thiourea under thermal and solvent-free conditions with good yields and short reaction times is reported. The most benefits of this synthetic method include the use of an efficient, eco-friendly, inexpensive and non-toxic catalyst, as well as the solvent-free conditions. All products were characterized by 1H NMR spectroscopy and melting point determination.