Convenient synthesis of novel sulfonamide derivatives as promising anticancer agents

Novel sulfonamide derivatives have been synthesized from the readily accessible N-(4-acetylphenyl)benzenesulfonamide (1) . Condensation of 1 with phenylhydrazine in refluxing ethyl alcohol gave the corresponding phenylhydrazone 2 , which was then added to the Vilsmeier-Haack reagent (POCl₃/DMF) to give the 4-formylpyrazole derivative 3 . Fusion of 1 with thiourea in the presence of iodine at 130°C afforded the 2-aminothiazole derivative 4 . Refluxing 1 with an excess of N, N-dimethylformamide dimethyl acetal furnished the enaminone 5 . The chemical reactivity of enaminone 5 toward some nitrogen and carbon nucleophiles has been studied to obtain polyfunctionalized heteroaromatic systems bearing a sulfonamide moiety. Besides, the enaminone 5 undergoes the Gewald reaction and reacts with ethyl cyanoacetate and elemental sulfur in the presence of morpholine to yield the 2-aminothiophene derivative 18 . Moreover, the utility of 5 for the synthesis of 4-(phenylsulfonamido)benzoic acid (19) was investigated. The synthesized sulfonamides were evaluated for their in vitro cytotoxic activities against two human cell lines, MCF-7 (breast adenocarcinoma cells) and RPE-1 (normal retina pigmented epithelium cells). The results revealed that compounds 1-3 , 6-8 , 10 , 12b , 18 , 19 , and 21 have a potent cytotoxic effect on MCF-7 and less on RPE-1 cells compared to the positive control doxorubicin®.