Synthesis and anticonvulsant activity of novel quinazolin-4(3H)-one derived pyrazole analogs

Eighteen novel 6,8-(dibromo/unsubstituted)-2-(methyl/phenyl)-3-(4-(5-(substitutedphenyl)-3-phenyl-4,5-dihydro-1H-pyrazole-1-carbonyl)phenyl)-quinazolin-4(3H)-ones 4a–4r were designed and synthesized in good yield. Antiepileptic screening of the title compounds was performed using MES and scPTZ seizures tests while the neurotoxicity was determined by rotorod test. In the preliminary screening, compounds 4d, 4e, 4p, 4q, and 4r were found active in MES model, while 4a, 4d, 4f, 4m, and 4p showed significant antiepileptic activity in scPTZ model. Further, all these eight compounds were administered to rats and compounds 4e, 4p, and 4q showed better activity than Phenytoin in oral route. Among these compounds 4p revealed protection in MES after i.p. administration at a dose of 30 mg/kg (0.5 h) and 100 mg/kg (4 h). The compound 4p also provided protection in the scPTZ at a dose of 100 mg/kg (0.5 h) and 300 mg/kg (4 h).