Two novel Br?nsted acidic ionic liquids 1-(4-sulfonic)-benzyl-3-methylimidazolium hydrogen sulfate (3a) and N-(4-sulfonic)-benzyl-pyridium hydrogen sulfate (3b) were synthesized using N-methyli- midazole and pyridine as starting materials, which acted as catalyst and reaction medium for the synthesis of 2-substituted-4(3H)-quinazolinones under three-component, one-pot, and microwave irradiation conditions. Under the optimized conditions of n(2-amino-benzoic acid)∶n(acylchloride)∶n(ammonium acetate)∶n(3a or 3b)＝1∶1.2∶1.5∶0.1, the reactions completed within 6 min with the yields of 81%～95%. 3a or 3b could be recycled three times without any significant loss in catalytic activity after reduced pressure distillation and drying under vacuum .

Key words: Br?nsted acid, ionic liquid, multi-component reaction, microwave, 4(3H)-quinazolinone