Synthesis, Characterization, and Anticancer Evaluation of New 2-Thioxo-4-imidazolidinone Derivatives against Human Breast Cancer Cells

A novel series of nine 2-thioxo-4-imidazolidinone derivatives (K1B, K2A, P1A, P1B, P2A, P2B, P4A, P4B, and T5B) was synthesized through a multi-step sequence comprising maleimide functionalization, hydrazide formation, and subsequent cyclization with isothiocyanates. The chemical structures of the newly developed compounds were comprehensively elucidated using FT-IR, 1H, 13C NMR, and mass spectrometry (MS). The in vitro cytotoxicity of these derivatives was evaluated against human breast cancer cells (MDA-MB-231) utilizing the MTT assay and morphological variation analysis. Compounds P2A, P1A, P2B, P4A, and T5B exhibited promising antiproliferative activity, displaying IC50 values of 23.24, 38.87, 41.92, 42.26, and 49.82 µM, respectively. These findings highlight the 2-thioxo-4-imidazolidinone (thiohydantoin) framework as a viable and promising scaffold for anticancer drug discovery. Further investigations are warranted to clarify the underlying molecular mechanisms of action and establish comprehensive selectivity profiles.