Synthesis, Characterization, Crystal Structure, and Antitumor Activity of 2-Phenylthiazole-Coumarin Derivatives

2-(4-Methoxyphenyl)-1,3-thiazole4-carboxylic acid was synthesized by condensation, alkylation, and saponification reactions using 4-hydroxythiobenzamide and ethyl 3-bromopyruvate as raw materials. It was then reacted with alpha,omega-dibromoalkanes to obtain omega-bromoalkyl 2-(4-methoxyphenyl)-1,3-thiazole-4-carboxylates which were condensed with 7-hydroxycoumarins. The structure of the synthesized omega-(2-oxo-2H-chromen-7-yloxy)alkyl 2-(4-methoxyphenyl)-1,3-thiazole-4-carboxylates was confirmed by IR, NMR, and mass spectra and single crystal X-ray diffraction. Their antiproliferation activity against MCF-7 and cisplatin-resistant MCF-7/DDP human breast cancer cell lines was evaluated by using CCK-8 assay. All compounds showed some inhibitory effect at a concentration of 50 mu M, and two compounds were found to be potent on both cancer cell lines.