Utility of 3-Acetyl-6-bromo-2H-chromen-2-one for the Synthesis of New Heterocycles as Potential Antiproliferative Agents

Coumarin derivatives containing pyrazolo[1,5-a]pyrimidine, tetrazolo[1,5-a]pyrimidine, imidazo[1,2-a]pyrimidine, pyrazolo[3,4-d]pyrimidine, 1,3,4-thiadiazoles and thiazoles were synthesized from 6-bromo-3-(3-(dimethylamino)acryloyl)-2H-chromen-2-one, methyl 2-(1-(6-bromo-2-oxo-2H-chromen-3-yl)ethylidene)hydrazine carbodithioate, 2-(1-(6-bromo-2-oxo-2H-chromen-3-yl)ethylidene)hydrazine carbothioamide and each of heterocyclic amine, hydrazonoyl chlorides and hydroximoyl chlorides. The structures of the newly synthesized compounds were elucidated on the basis of elemental analysis, spectral data, and alternative synthetic routes whenever possible. Moreover, selected newly synthesized products were evaluated for their antitumor activity against a liver carcinoma cancer cell line (HEPG2-1). The results revealed that pyrazolo[1,5-a]pyrimidine 7c, thiazole 23g and 1,3,4-thiadiazole 18a (IC50 = 2.70 +/- 0.28, 3.50 +/- 0.23 and 4.90 +/- 0.69 mu M, respectively) have promising antitumor activity against liver carcinoma (HEPG2-1) while most of the tested compounds showed moderate activity.