A microwave-assisted and heteropolyacids-catalysed cyclocondensation reaction for the synthesis of 4(3H)-quinazolinones.

We have investigated a microwave–assisted synthesis of 4(3H)–quinazolinonesby condensation of anthranilic acid, orthoesters (or formic acid) and substituted anilines,using Keggin-type heteropolyacids (H3PW12O40·13H2O, H4SiW12O40·13H2O,H4SiMo12O40·13H2O or H3PMo12O40·13H2O) as catalysts. We found that the the use of H3PW12O40·13H2O acid coupled to microwave irradiation allows a solvent-free, rapid (~ 13min) and high-yielding reaction.