3,3′-(butane-1,4-diyl)bis(1,2-dimethyl-1H-imidazol-3-ium) dibromide [BDBIm] Br-An efficient reusable ionic liquid for the microwave-assisted synthesis of quinazolinones

A series of 2-substituted quinazolin-4(1H)-ones have been synthesized in excellent yields and short reaction times by one-pot reaction of isatoic anhydride with ammonium acetate and aromatic aldehydes under microwave irradiation. The reaction was efficiently promoted by 0.5 mmol of 3,3′-(butane-1,4-diyl)bis(1,2-dimethyl-1H-imidazol-3-ium) dibromide [BDBIm] Br, and the catalyst could be recovered easily and reused without appreciable loss of reactivity.