In the present work we have designed and synthesized novel pyrimidine derivatives by condensing Acetyl benzimidazole with various aromatic and heteroaromatic aldehyde and cyclized into pyrimidine derivatives by reacting with Guanidine HCl. These synthesized pyrimidine derivatives screened for anticancer activity. Among the 12 Pyrimidine derivatives, four compounds shown IC50 values in the range 15.45-40.08 µg/ml range and found more potent than standard anticancer drug 5-Flurouracil which shown IC50 value 41.56 µg/ml on the MCF-7 cell line. Among 12 pyrimidine derivatives, IC 23 rd. pyrimidine derivative shown IC50 Value 15.45 µg/ml on the MCF-7 cell line which demonstrate promising anticancer activity. Molecular docking study also performed on telomerase active pocket to find out favourable interactions of pyrimidine derivatives, result shown that all compounds have good binding interaction with receptor.