The present study was aimed at synthesizing isatin-5-sulphonamide derivatives are prepared by chlorosulphonation of isatin to prepare isatin-5-sulphonic acid chloride and it is subjected to reaction with different amines or anilines to form respective sulphonamide derivatives. The new compounds were characterized based on spectral (FT-IR, NMR and Mass) analysis. All the test compounds showed CNS depression while studying the gross behavioral changes. All the test compounds exhibited reduction in locomotor activity. Compound IIIf (R = p-toluidino) showed more reduction in the locomotor activity among all the test compounds. Compounds IIId, IIIc, IIIb, IIIa were next in the order of reduction of locomotor activity. The compounds were evaluated for anticonvulsant activity against maximum electric shock induced and Pentylenetetrazol (PTZ) induced seizures in mice using phenytoin as a standard.