A favourable ultrasoundassisted method for the combinatorial synthesis of 2,3- dihydroquinazolin-4(1H)-ones via CoAl2O4 spinel nanocrystal as an efficient catalyst

Mesoporous CoAl2O4 spinel nanocrystals ( nano-CoAl2O4 ) were synthesized and fully characterized by X- ray diffraction patterns (XRD), energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), DLS (dynamic light scattering) and FT-IR. The nanocrystals promoted the preparation of quinazolinones via the one-pot, three component condensation reaction of benzaldehydes, isatoic anhydride, primary aromatic amine or ammonium acetate at 45°C under ultrasound irradiation. Experimental simplicity, great yields in concise times, the retrievability of the nanocrystals and performing the sonochemical methodology as an effective way in synthetic chemistry for the preparation of medicinally privileged heterocyclic molecules are some of the substantial features of this method. The present catalytic process is applicable to an extensive diversity of substrates for the preparation of a variety-oriented library of dihydroquinazolinones. The feasibility of doing one-pot synthesis under ultrasonic irradiation with a heterogeneous nanocrystal could improve the reaction rates and shorten the reaction times.