rel-2-[4-Chloro-2-[(5R,6R,7S)-6-[5-(4-methoxyphenyl)-3-(2-naphthyl)-3,4-dihydropyrazole-2-carbonyl]-5-methyl--2-oxo-3,5,6,7-tetrahydrothiopyrano[2,3-d]thiazol-7-yl]phenoxy]acetic Acid

The hetero-Diels-Alder reaction is the main synthetic tool for obtaining pharmacological agents with a thiopyrano[2,3-d]thiazole motif. In the present work, an efficient method for the synthesis of pyrazoline-containing thiopyrano[2,3-d]thiazole is described. The pyrazoline-bearing dienophile was proposed and used as effective building block for the synthesis of the title compound. The structure of the synthesized rel-2-[4-chloro-2-[(5R,6R,7S)-6-[5-(4-methoxyphenyl)-3-(2-naphthyl)-3,4-dihydropyrazole-2-carbonyl]-5-methyl-2-oxo-3,5,6,7-tetrahydrothiopyrano [2,3-d] thiazol-7-yl] phenoxy]acetic acid (3) was confirmed by H-1, C-13, 2D NMR, and LC-MS spectra. Anticancer activity in "60 lines screening" (NCI DTP protocol) was studied in vitro for the title compound.