Abstract: A series of five membered heterocyclics was synthesized by the reaction between isoniazid and various substituted isothiocyanates and was tested for their anticonvulsant activity by determining their ability to provide protection against convulsions induced by electroconvulsometer. Among the synthesized compounds,(IIf) 2-(4-chlorophenyl) amino-5- (4-pyridyl)-1, 3, 4-thiadiazole and (IIIf) 2-(4-chlorophenyl) amino-5-(4-pyridyl)-1, 3, 4- ...