Synthesis, biological evaluation, molecular docking and DFT calculations of novel benzenesulfonamide derivatives

Abstract

The reaction of N-(4-acetylphenyl)benzene sulphonamide derivatives 3a and 3b with N,N dimethyl formamide dimethyl acetal (DMF-DMA) afford acryloyl(phenyl)benzenesulfonamide derivatives 4a and 4b; respectively. The chemical reactivity of enaminonitriles 4a and 4b towards hydrazine hydrate or hydroxylamine was studied for synthesizing of pyrazolyl and isoxazolyl-phenyl benzenesulfonamide derivatives 5a,b and 6a,b; respectively. Also, the treatment of enaminonitriles 4a and 4b with thiosemicarbazide or heterocyclic amines derivatives afford the novel sulfonamide derivatives. Furthermore, the reactivity of acetylsulfonamide derivatives towards nitrogen nucleophiles and dimedone afforded novel benzene sulfonamide compounds. Some of the synthesized chlorinated compounds exhibited excellent in vitro antitumor activity against HepG2 and MCF-7 cell lines. Additionally, further studies were carried out on one of the most effective compounds, 4-chloro-N-(4-(isoxazole-3-yl)phenyl) benzenesulfonamide 6a (ISP), to evaluate its potential interaction against KSHV thymidylate synthase complex. The comprehensive theoretical and experimental mechanical studies of compound 6a (ISP) were compatible with elemental analysis, FTIR, 1H NMR and MS spectral data. The optimized molecular structure and the harmonic vibrational frequencies were examined via Density functional theory (DFT)/B3LYP/6-31G(d) and Hartree-Fock HF/6-31G(d) energies.