NOVEL SULFONAMIDE DERIVATIVES

Sulfonamide derivatives represented by general formula (1) or pharmaceutically acceptable salts thereof, which have little toxicity and a potent effect of inhibiting tubulin polymerization wherein R1 preferably represents lower alkoxy; R2, R3, R4, R5 and R6 may be the same or different and each independently represents hydrogen, halogeno, nitro, lower alkyl, optionally substituted amino or alkylamino; A represents: (1) a 5-membered heterocyclic group having at least one nitrogen atom which may be substituted and contain as the heteroatom an atom selected from among nitrogen, oxygen and sulfur, provided that triazole is excluded therefrom; (2) an optionally substituted alicyclic hydrocarbon group; or (3) an alicyclic hydrocarbon group containing at least one nitrogen atom in the cycle and capable of further containing nitrogen, oxygen or sulfur as the heteroatom. Drugs containing these compounds as the active ingredient correct abnormalities in the immune system and, therefore, are useful as preventives or remedies for rheumatism such as inflammatory rheumatism or as anticancer agents.