Efficient and green protocols were reported to synthesize 2,3-dihydroquinazolin-4(1H)-one derivatives in natural deep eutectic solvent (NADES). NADES was prepared from ascorbic acid (AA) and choline chloride (ChCl) with reduced or null toxicity, biocompatibility, and low cost. The ChCl/AA NADES was successfully used in the synthesis of 2,3-dihydroquinazolin-4(1H)-one derivatives via the condensation reaction of aldehydes with 2-aminobenzamide and the threecomponent reactions of aldehydes, isatoic anhydrides and ammonium salts under solvent-free conditions. The scope of this method was evaluated by employing various aromatic, heterocyclic, and aliphatic aldehydes. The desired products were achieved in 85–97 % yield in a short reaction time. Also, the deep eutectic solvent ChCl/AA showed good recyclability and reusability.
