Chalcone-quinolinone hybrid compounds, as well as the synthesis of such compounds, have few reports in the literature. Such compounds may be quite useful in therapeutics, since various biological activities are reported for both chalcones and quinolinones. In the present work, several novel chalcone-quinolinone compounds have been synthesized. The reaction conditions developed allowed to obtain the compounds in a single step of synthesis from the chalcones. The products precipitated pure and were isolated by filtration. The yields of such reactions, from 45 to 94%, were promising. The product structures were confirmed by nuclear magnetic resonance (NMR) and electrospray ionization mass spectrometry (ESI-MS) techniques. Their antitumor activities were evaluated in HCT-116 (colon) cell lines by the 3-(4,5-dimethyl-2-thiazole)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) test. The half maximal inhibitory concentration (IC50) values obtained for the most active chalcones were between 2.9 and 7.5 and for active quinolinone was 19.3 mg L-1. The antitumor activities results suggest that the class of compounds studied has potential for use in cancer research.

Four sulfonamide-chalcone derivatives were prepared and their crystal structure were elucidated by single-crystal X-ray diffraction technique. They were synthesized by Claisen-Schmidt condensation reaction between N-(4-acetylphenyl)benzenesulfonamide or N-(4-acetylphenyl)-2,5-dichlorobenzenesulfonamide with benzaldehyde or p-nitrobenzaldehyde. Values of Z' > 1 are found in three compounds as a consequence of conformerism. The chalcone molecular backbones are featured by different levels of planarity in their conformers. Another conformational variability is in its benzenesulfonamide moiety. In the compound came from N-(4-acetylphenyl)benzenesulfonamide and benzaldehyde, there is a rotation of ca. 180° on the bond axis bridging the sulfonamide and chalcone motifs of one conformer if the two others are taken as references. The cytotoxic activity of all compounds synthesized here and of two other related sulfonamide chalcones was also assessed against three cancer cell lines (SF-295, HCT-8 and MDA-MB-435). The para-nitro compounds were the most active ones among all those tested, regardless of substitution pattern in benzenesulfonamide core.