The versatile synthons 2-chloro-N-(4-sulfamoylphenyl)acetamides la,b were used as a key intermediates for the synthesis of sulfonamide derivatives with adamantyl 2, indene 3, morpholinophenyl 4, pipronyl 5, benzothiazole 6-8, pyrazole 9, thiadiazole 10,11, quinoline 12, isoquinoline 13, thiazoles 14-19, acrylamides 20-24 and benzochromene 25 moieties via reaction with several nitrogen nucleophiles. The newly synthesized compounds were screened in vitro for their anticancer activity against breast cancer (MDA-MB-231) and colon cancer (HT-29) cell lines. Compound 17 was found to be the most potent against breast cancer cell lines with IC55 value 66.6 μM compared with the reference drug 5-fluorouracil with IC50 value 77.28 μM.