Utility of 2-Acetyl Benzofuran for the Synthesis of New Heterocycles as Potential Anticancer Agents

A novel series of benzofuran derivatives containing thiazole, thiadiazine, and pyridotriazolopyrimidine were synthesized starting from 1-(benzofuran-2-yl)-3-(1H-indol-3-yl) prop-2-en-1-one. Also, triazolopyrimidine derivatives were prepared from the reaction of 2-acetylbenzofuran and pyrazole-4-carbaldehyde with 2-thiobarbutyric acid and reaction of the product with hydrazonoyl halides. The structures of the newly synthesized compounds were elucidated on the basis of elemental analyses, spectral data, and alternative synthetic routes whenever possible. Anticancer activity against 60 different human tumor cell lines representing leukemia, melanoma, and cancers of the lung, colon, brain, ovary, breast, prostate, and kidney was validated by the U.S. National Cancer Institute using a two-stage process. The results revealed that pyrazoline-1-thiocarbohydrazide 4b, triazolopyrimidine 20d, and pyrimidine thione 25 have promising antitumor activity against most cell lines.