A library of acetamide and hydrazine analogues were generated on the pyrimidine ring through a multistep reaction starting from 5‐nitro‐pyrimidine‐4,6‐diol and pyrimidine‐4,6‐diol, respectively. The synthesized analogues were screened for in vitro cytotoxic activity against various human cancer cell lines like HCT‐1 and HT‐15 (colon), MCF‐7(breast), PC‐3 (prostrate), SF268 (CNS) using MTT method. From the bioassay results, it was observed that even though many of the synthesized derivatives exhibited a good potency against various screened cancer cell lines, compound 14a from the acetamide series was found to show potent anticancer activity on all the tested cancer cell lines with IC50 value of 0.36μM on CNS cell line and 1.6μM on HT‐21 cell line, and compound 19xxi from hydrazine series of pyrimidine showed potent activity against three tested cancer cell lines with IC50 value of 0.76μM on HT‐29 cell line, 2.6μM on HCT‐15, and 3.2μM on MCF‐7 cell line.