Synthesis of pyrazol-quinazolinones and 2,3-dihydroquinazolin-4(1H)-ones using CoAl2O4 nanoparticles as heterogeneous catalyst

The preparation and characterization of cobalt aluminate (CoAl2O4) magnetic nanoparticles and its application as a catalyst for the synthesis of a novel class of pyrazol-quinazolinones and 2,3-dihydroquinazolin-4(1H)-ones is described. The structure of the catalyst was studied by Fourier transform infrared spectroscopy, transmission electron microscopy, X-ray diffraction, and vibrating sample magnetometer analysis. The resulting cobalt aluminate (CoAl2O4) was an efficient catalyst and affords the desired products in good to excellent yields. Moreover, the catalyst could be easily recovered by magnetic separation and recycled for four times without significant loss of its catalytic activity. 2,3-Dihydroquinazolin-4(1H)-ones and a novel class of pyrazol-quinazolinones were synthesized through one-pot condensation reaction of isatoic anhydride, aromatic aldehydes, and amines using CoAl2O4 as nanoparticle heterogeneous catalyst in refluxing ethanol.