Acta Pharm. 53 (2003) 127-138

Design and synthesis of some new derivatives of 3H-quinazolin-4-one
with promising anticonvulsant activity

ABDEL GHANY ALY EL-HELBY^1* and MOHAMMED HEMEDA ABDEL WAHAB² 

menazmd@hotmail.com

¹Department of Pharmaceutical Chemistry
²Department of Pharmacology, Faculty of Pharmacy, Al-Azhar University Nasr City, Cairo, Egypt

A new series of 3-substituted (methyl, ethyl or phenyl)-3H-quinazolin-4-one derivatives (4a-l) were synthesized through condensation reaction of their potassium salts (3a-l) with methyl, ethyl and phenylisocyanate. The newly synthesized derivatives (4a-l) were evaluated for anticonvulsant activity. It was found that these compounds showed highest anticonvulsant activity at low doses (50-100 mg kg^-1), whereas at dose over 100 mg kg^-1 they showed stimulant effect on central nervous system that even potentiated the effect of convulsive agent, pentylenetetrazole, in mice. A series of halogenated derivatives, 3-methyl, 3-ethyl and 3-phenyl-6-mono and 6,8-disubstituted-3H-quinazolin-4-one derivatives (4m-z) was also synthesized and evaluated for anticonvulsant activity. Reduced anticonvulsant activity was recorded. Phenobarbitone sodium was used as a reference drug.

Keywords: 3H-quinazolin-4-one derivatives, synthesis, anticonvulsant activity