A set of novel 1-aryl-6, 7-methylenedioxy-3H-quinazolin-4-(thi) ones (3a–f) has been designed and screened as anticonvulsant agents in DBA/2 mice. The new compounds are provided with anticonvulsant properties comparable to those of GYKI 52466. To clarify the mode of action, their affinity for the quinazolinone/2, 3-benzodiazepine site of the AMPA receptor complex has been assayed.