Design and synthesis of certain imidazo[1,5-a] quinazolin-5 [4H]-ones of anticipated anticonvulsant activity

ABSTRACT

1 -[alkyl/aryl] - 3 - [1 - [4' -chlorophenyl] - 5 [4H] - oxo - imidazo [l,5-a]quinazolin-4-yl] thiourea 5 derivatives were synthesized from 4-amino-1-[4'-chlorophenyl] imidazo [1,5-a] quinazolin-5[4H]-one 4 which were cyclized into the corresponding thioxoimidazolidindiones 6, thiazolidinones 7 and 8, or 2,3-dihydrothiazol-4-ol 9. Also, some derivatives 10 were synthesized through the reaction of 4 with 5[4H]-oxazolone derivatives. Furthermore, 2-chloro-N-[l -[4'-chlorophenyl]-5[4H]-oxoimidazo[1,5-a] quinazolin-4-yl]acetamide 11 was reacted with sodium valproate or potassium 2-or 4-[3-substituted phenyl or cyclohexyl ureido]benzoate derivatives to give 12 or 13, respectively. Molecular modeling study was achieved to reveal the anticonvulsant activity of the newly synthesized derivatives postulating a hypothesis based on the specific binding with benzodiazepine receptor. Representative examples were chosen and screened for their anticonvulsant activity