Benzofuran derivatives are of great interest in medicinal chemistry and have drawn considerable attention due to their diverse pharmacological profiles including anticancer activity. Similarly, chalcones, which are common substructures of numerous natural products belonging to the flavonoid class, feature strong anticancer properties. A novel series of chalcones, 3-aryl-1-(5-bromo-1-benzofuran-2-yl)-2-propanones propenones (3a–f), were designed, synthesized, and characterized.In vitroantitumor activities of the newly synthesized (3a–f) and previously synthesized (3g–j) chalcone compounds were determined by using human breast (MCF-7) and prostate (PC-3) cancer cell lines. Antitumor properties of all compounds were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cell viability assay for the tested chalcone compounds was performed and thelog⁡IC50values of the compounds were calculated after 24-hour treatment. Our results indicate that the tested chalcone compounds show antitumor activity against MCF-7 and PC-3 cell lines (p<0.05).

2‐Acetylbenzofuran on condensation with furan‐2‐carboxaldehyde and pyrrole‐2‐carboxaldehyde in methanolic KOH solution yielded the corresponding benzofuran chalcones. These two compounds and nine benzofuran chalcones were synthesized before, were further reacted with hydrazine hydrate in ethanol which led to the formation of 2‐pyrazoline derivatives. All the synthesized compounds were characterized by elemental analysis, melting point determination, infrared spectroscopy and nuclear magnetic resonance spectroscopy. Nine chalcone‐type compounds and eleven 2‐pyrazolines were evaluated for their biological activities against the six bacteria and the three yeast and it was seen that thirteen compounds showed activity. Four of them are chalcone‐type compounds showed more or less activity.