AbstractBreast cancer is a potentially deadly disease that affects millions of individuals worldwide. Therefore, it is crucial to design highly targeted therapeutic techniques with low toxicity. In this work, we synthesized natural product Herdmanine's ester derivatives and tested them against EGFR and HER2 proteins as multitargated inhibitor of breast cancer progression. Further, the newly synthesized compounds were evaluated for cytotoxicity against breast cancer cell lines MCF‐7, MDA‐MB‐231 and MDA‐MB‐157 and the biocompatibility towards NIH 3T3 cells. Higher toxicity and positive viability profiles of Herdmanine derivatives indicate their potential use for further exploration in breast cancer application.