Studies On Copper-mediated Synthesis Of Quinazolin-4(3H)-ones

Quinazolinones are widely found in a variety of natural products and drugs,which have significant pharmacological activities and can be used as anticancer drugs,antihypertensive drugs,anti infective drugs,anticonvulsant drugs and so on.O-amino or o-halobenzamide as the substrate can react with alcohol,aldehyde,arene,N-arylbenzylamine to synthesize quinazolinone.In addition,o-halobenzoic acid and amidine hydrochloride can also react with o-aminobenzonitrile and alcohol to synthesize quinazolinone.In the part of research work,we have developed a new method for the synthesis of quinazoline-4(3H)-one from N-(quinoline-8-yl)benzamide and benzamidine hydrochloride with anhydrous copper acetate as catalyst.The method involved the activation of C(sp~2)-H and the formation of C-N bond.The complex formed by copper(?)and N-(quinoline-8-yl)benzamide plays an important role in the reaction.Quinozoline-4(3H)-one was formed by the departure of the line group and the nucleophilic substitution reaction on the intramolecular carbonyl group.The reaction is characterized by easily available starting materials,simple operation,a broad substrate scope and excellent yields.