Synthesis of novel 1,3-thiazin-4-ones by acetylene diester cyclization and their anticancer activities

A novel series of 1,3-thiazin-4-one derivatives containing a piperidyl ring (7-16) were designed and synthesized efficiently by thioamide and acetylene diester cyclization reaction via aminolysis of the ester group and the elimination of an alcohol molecule. The structures of all the novel compounds were established by their FTIR, Mass, H-1 NMR, and C-13 NMR spectral techniques. The newly synthesized compounds (7-16) were studied for their in vitro anticancer activity against human liver cancer cell lines Hep G2 using MTT assay. The IC50 values of the tested compounds were ranging in between 7.48 +/- 0.71 and 56.57 +/- 1.37 mu M. Further, the apoptosis evaluation by the mitochondrial membrane potential using JC-1 dye was carried out and the results are in good agreement with the cytotoxicity studies. [GRAPHICS] .