Design, Synthesis, and Evaluation of Pyrrolopyrazine‐Substituted Benzoxazole/Benzothiazole Derivatives Targeting Aurora Kinase A in MCF‐7 Cells

Abstract This study reports the synthesis, characterization, and biological evaluation of 19 benzoxazole/benzothiazole hybrids ( 19a‐s ). The compounds were synthesized through a multi‐step process and structurally confirmed via NMR, elemental, and MS analyzes. Their antiproliferative effects were assessed on MCF‐7 breast cancer and HME1 healthy epithelial cells. MTT assays identified 15 compounds with significant cytotoxic activity, among which 19e , 19g , 19i , 19j, and 19k exhibited high selectivity for MCF‐7 cells. ELISA results demonstrated that 19g , 19i , 19j , and 19k significantly reduced AURKA protein levels in MCF‐7 cells, while sparing healthy cells, suggesting their role in inhibiting cancer cell proliferation. These findings highlight 19g , 19i , 19j , and 19k as promising selective AURKA‐targeted agents for breast cancer therapy.