ZrP2O7 nanoparticles as a robust and efficient catalyst for the synthesis of 2-aryl-5-methyl-2,3-dihydro-1H-3-pyrazolones under microwave irradiation

ZrP2O7 nanoparticles have been used as an efficient catalyst for the preparation of 2-aryl-5-methyl-2,3-dihydro-1H-3-pyrazolones by a simple one-pot four-component reaction of phenyl hydrazines, ethyl acetoacetate ,β-naphthol and benzaldehydes under microwave irradiation in good to excellent yields. When the reaction was carried out using ZrOCl2.8H2O, ZrO2 and ZrP2O7 NPs as the catalyst, the product were obtained in moderate to good yield. The highest yield 92% was reached when the reaction was performed with 0.6 mol% of catalyst loading. Atom economy, green reaction, short reaction times, easy isolation of the targeted molecules, recovery and reusability of the catalyst are some of the important features of this protocol.