an improved, simple, and facile synthesis of 3,4-dihydropyrimidin-2(1h)-ones by employing three-component, one-pot condensation reaction of β-keto ester, aromatic aldehydes, and urea or n-methylurea using lacl3/clch2cooh as an inexpensive and green chemistry catalyst system under solvent-free conditions described. compared with the classicalbiginelli reaction conditions, this method has the adv...

a simple and green chemical procedure was reported for the synthesis of dihydropyrimidinones from various aldehydes, ethyl acetoacetate and urea or thiourea using  holmium chloride as catalyst. the reactions were performed under solvent free conditions with ultrasound irradiation as the energy source. the advantages of this protocol include the excellent yield, operational simplicity, short tim...

A simple and green chemical procedure was reported for the synthesis of dihydropyrimidinones from various aldehydes, ethyl acetoacetate and urea or thiourea using  holmium chloride as catalyst. The reactions were performed under solvent free conditions with ultrasound irradiation as the energy source. The advantages of this protocol include the excellent yield, operational simplicity, short tim...