A series of azaheterocyclic carbazole sulfonamides was synthesized and evaluated for antiproliferative activity. The most potent compounds N-(2, 6-dimethoxypyridine-3-yl)-9-ethyl and 9-methylcarbazole-3-sulfonamide (13 and 14) gave significant cytotoxicity (IC50= 122 and 101nM). Compound 13 displayed submicromolar activities against seven human tumor cell lines. The SARs of this series of sulfonamides which includes the influence of ...