Many derivatives of heterocyclic compounds containing a sulfonamide thiazole moiety were synthesized through the reaction of 2‐(cyano or chloro)‐N‐(4‐(N‐thiazol‐2‐ylsulfamoyl)phenyl)acetamide with isocyanate followed by halogenated compounds, arylidene, 2‐hydroxy benzaldehydes, active methylene compounds, and heterocyclic amines. The anticonvulsant activity for 15 of the synthesized compounds was evaluated and 6 compounds showed protection against picrotoxin‐induced convulsion. 4‐(6‐Amino‐3,5‐dicyano‐4‐(4‐methoxyphenyl)‐2‐oxopyridin‐1(2H)‐yl)‐N‐(thiazol‐2‐yl)benzenesulfonamide (11b) exhibited significant anticonvulsive effects, abolished the tonic extensor phase and offered 100% protection.