1,4-Naphthoquinone Motif in the Synthesis of New Thiopyrano[2,3- d ]thiazoles as Potential Biologically Active Compounds.

A series of 11-substituted 3,5,10,11-tetrahydro-2 H -benzo[6,7]thiochromeno[2,3- d ][1,3]thiazole-2,5,10-triones were obtained via hetero -Diels-Alder reaction of 5-alkyl/arylallylidene/-4-thioxo-2-thiazolidinones and 1,4-naphthoquinones. The structures of newly synthesized compounds were established by spectral data and a single-crystal X-ray diffraction analysis. According to U.S. NCI protocols, compounds 3.5 and 3.6 were screened for their anticancer activity; 11-Phenethyl-3,11-dihydro-2 H -benzo[6,7]thiochromeno[2,3- d ]thiazole-2,5,10-trione ( 3.6 ) showed pronounced cytotoxic effect on leukemia (Jurkat, THP-1), epidermoid (KB3-1, KBC-1), and colon (HCT116wt, HCT116 p53-/-) cell lines. The cytotoxic action of 3.6 on p53-deficient colon carcinoma cells was two times weaker than on HCT116wt, and it may be an interesting feature of the mechanism action.