Compounds 101, 102 and 103 ( Fig. 9 ) displayed the most potent protective potency against pentylenetetrazole (PTZ)-induced clonic seizures in mice at a dosage level of 20 mg/kg with the protective ratio for 74.5, 78.7 and 74%, respectively, which was close to phenobarbital sodium (30 mg/kg) and better than phenytoin sodium (30 mg/kg).