Microwave-assisted synthesis of quinazolinone derivatives by efficient and rapid iron-catalyzed cyclization in water

A green, rapid, and efficient method was developed for synthesizing quinazolinone derivatives from substituted 2-halobenzoic acids and amidines via microwave-assisted iron-catalyzed cyclization with or without ligand in water (methods A and B) or DMF (methods C and D). With these methods, moderate to high yields of the desired products can be obtained from even inactive substrates, such as guanidines. To the best of our knowledge, this is the first report on the synthesis of N-heterocyclic compounds by iron-catalyzed C–N coupling in aqueous media.