Quinazolin-4(3H)-ones represents a useful nucleus for preparation of some new antibacterial, antitubercular, antiviral, anticancer and anticonvulsant agents, since such a heterocyclic system possesses the pharmaphoric moiety. Structure activity relationship studies of quinazolinone ring system in various literatures suggest position 2, 6 and 8 are very much important for structure activity studies and position 3 should be attached to different secondary amines for better pharmacological activities