Design, synthesis, molecular docking of new thiopyrimidine-5-carbonitrile derivatives and their cytotoxic activity against HepG2 cell line

A series of new thiopyrimidine derivatives were synthesized via the reaction of ethyl cyanoacetate with thiourea and the appropriate aldehydes namely, 3-methoxy-benzaldehyde, 2, 5-dimethoxy-benzaldehyde and 3,5-dimethoxy-benzaldehyde to give the corresponding pyridine thiones 1a-c. Compounds 1a-c were then chlorinated to give the corresponding chloro compounds 2a-c, which then underwent variant cyclocondensation reactions to afford different cyclized compounds 3-10. On the other hand, 1a-c were condensed with monochloroacetic acid and different aldehydes to give 11-14. Some of the new derivatives were selected for cytotoxicity evaluation against HepG2 cell line in comparison to 5-FU as a reference drug. Among all tested compounds, compound 4a was the most potent with IC50 value of 13.18 µM. Furthermore, a docking study of the most active compounds was carried out with thymidylate synthase enzyme. Structures of all new compounds were elucidated by their correct elemental analysis and spectral data.