Heterocyclic chemistry comprises at least half of all organic chemistry research worldwide. Quinazolinones are the versatile nitrogen containing heterocyclic compounds. Earlier it is known as benzo-1,3-diazine and was first prepared in laboratory by Gabriel in1903 and first isolated from the chinese plant aseru.1 The name quinazoline (German : Chinazolin) was first prepared by Weddige, on observing that this was isomeric with the compounds cinnoline and quinoxaline. Paal and Bush suggested the numbering of quinazoline ring system, which is currently used.2 Quinazolinones will be classified into the following five categories based on the substitution patterns of the ring system.3 • 2-substituted-4(3H)-quinazolinones • 3-substituted-4(3H)-quinazolinones …show more content…
Quinazolinone is a building block for approximately 120 naturally occurring alkaloids isolated till date from a number of families of the plant kingdom, microorganisms and animals. The first quinazolinone, i.e., 2-cyanoquinazolinone was synthesized in the late1860’s from anthranilic acid and was found to possess anti-convulsant activity. Interest in the medicinal chemistry of quinazolinone derivatives was stimulated in the early 1950’s with the elucidation of quinazolinone alkaloid i.e, 3-[ keto-(3-hydroxy-2-piperdiyl)-propyl]-4-quinazolone from an Asian plant Dichroa febrifugin, which is an ingredient of a traditional Chinese herbal remedy, effective against malaria. Methaqualone was synthesized for the first time in 1951 and it is the most well- known synthetic quinazolinone drug, famous for its sedative and hypnotic