Synthesis and anticonvulsant activity of some 2-pyrazolines derived from chalcones

All compounds were tested for their anticonvulsant activity using pentylenetetrazole induced seizure (PTZ) and maximal electroshock seizure (MES) tests in mice at a dose level of 50 mg/kg. Among the 2-pyrazoline-1-carbothioamide derivatives, 5-(2,6-dichlorophenyl)-3-(thiophen-2-yl)-4,5-dihydro-1H-pyrazole-1-carbothioamide (2e) reduced grade-5 seizure activity and also increased survival rate in PTZ test. In MES test, 5-(4-methoxyphenyl)-3-[4-(methylsulphonyl)phenyl]-4,5-dihydro-1H-pyrazole-1-carbothioamide(2g) has not only decreased seizure severity, but also increased survival rate. Among the 2-pyrazoline-1-carboxamide derivatives, 3-(5-bromothiophen-2-yl)-N-(4-chlorophenyl)-5-(2,6-dichlorophenyl)-4,5-dihydro-1H-pyrazole-1-carboxamide (3d) having 5-bromothiophen and 2,6-dichlorophenyl moieties and N-(4-chlorophenyl)-5-(2,6-dichlorophenyl)-3-(5-chlorothiophen-2-yl)-4,5-dihydro-1H-pyrazole-1-carboxamide (3e) having 5-chlorothiophen and 2,6-dichlorophenyl moieties showed remarkable activities in PTZ test. Among all tested derivatives, compound 3d was found to be the most active one and reduced grade-5 seizure severity and also increased survival rate.