A series of some novel 4‐(N‐substituted amino)‐acetanilide scaffolds was synthesized through the nucleophilic substitution reactions of the highly versatile N‐(4‐acetamidophenyl)‐2‐chloroacetamide (3) with various types of nucleophilic reagents such as benzothiazole‐2‐thiol, ethyl 2‐mercaptoacetate, 4,6‐dimethyl‐2‐mercapto‐nicotinonitrile, various thiocarbamoyl derivatives, ammonium thiocyanate, 3‐cyano‐4,6‐dimethyl‐5‐arylazopyridin‐2‐ones, and malononitrile. The synthesized 4‐(N‐substituted amino) acetanilide scaffolds were characterized by spectral analyses and assayed in vitro for breast anticancer activity. 2‐(4‐Acetamidophenylaminocarbonyl)‐3‐amino‐thiophenes 11, 13a, and 13b showed the highest cytotoxic activity.