Efficient synthesis of 2,3-dihydroquinazolin-4(1H)-ones using nano-sized protonated ZSMâ5 as a biodegradable and reusable solid acid catalyst

Abstract

Nano-sized protonated ZSMâ5 ( H-ZSM-5nanozeolite) was successfully synthesized by the hydrothermal method using the bagasse ash (BGA) as a new silica source. Cultivated BGA in the south of the Caspian Sea (Mazandaran province, Iran) was used for extracting silica powder. H-ZSM-5 was characterized by Fourier transform infrared (FT-IR), X-ray diffraction (XRD), scanning electronic microscopy (SEM) and BrunauerâEmmettâTeller (BET), Barrett-Joyner-Halenda (BJH) techniques. The catalytic activity of H-ZSM-5 nanozeolite was evaluated for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones via one-pot three-component reaction of aromatic aldehydes, 2-aminobenzothiazole or 2-aminobenzimidazole and isatoic anhydride under solvent-free conditions. Short reaction time, high yields, a simple experimental procedure in the absence of any toxic solvents and recovery of catalyst are the advantages of this protocol.