Boosting microwave-assisted synthesis via potash alum for bioactive spiro-benzothiazoles with its computational profile

A novel series of spiro-benzothiazole derivatives(3a-k) was synthesized using a green, microwave-assisted three-component reaction catalyzed by potash alum. The protocol offered excellent yields within 20 min, significantly outperforming conventional methods. All compounds were structurally confirmed by FT-IR, NMR, and ESI-MS, and their purity was validated by HPLC. Biological evaluation revealed that compound 3k exhibited the most potent cytotoxicity against MCF-7 breast cancer cells (IC50 = 0.58 µM), while compound 3a showed excellent antioxidant potential (IC50 = 0.52 µM). Antibacterial screening indicated that 3d was highly active against S. aureus and B. subtilis. Molecular docking studies highlighted compounds 3k, 3c, and 3d as strong inhibitors of the 3EQM breast cancer-associated protein, with 3k showing stable hydrogen bonding, halogen bonding, and π-π stacking interactions. Further, 100 ns molecular dynamics simulations confirmed the conformational stability of 3k, while ADME-Tox predictions indicated favourable drug-likeness. These results identify spiro-benzothiazoles, particularly compound 3k, as promising multifunctional leads for anticancer, antioxidant, and antibacterial applications.