The present study describes the synthesis and antiproliferative evaluation of several neocryptolepine analogues carrying sulfonamide side chain at C11. The key intermediate compound amine 7 was prepared by nucleophilic aromatic substitution (S_NAr) of 11-chloroneocryptolepines 5 with 4, 4'-diaminodiphenylmethane 6. The 11-diamino derivatives 7 were further reacted with arylsulfonly chlorides 8 to afford the corresponding 11-sulfonamide neocryptolepine analogues 9. Some of the prepared neocryptolepine derivatives showed a strong antiproliferative activity against the breast, colon and hepatocellular carcinoma cell lines. Among them, compound 9c was the most cytotoxic with a mean IC₅₀ value of 8.95 μM, 14.24 and 11.76 μM against the breast, colon and hepatocellular carcinoma cell lines respectively.