Synthesis, Characterization, Thermal and Antimicrobial studies of N-substituted Sulfanilamide derivatives

• Synthesized four sulfanilamide derivatives.
• Characterized by IR NMR and Mass spectra.
• Single crystal X-ray diffraction study was done.
• The thermal behavior study was done by TGA and DSC methods.
• Antimicrobial activity was studied.

Four sulfanilamide derivatives N-[4-(phenylsulfamoyl)phenyl]acetamide (1), 4-amino-N-phenylbenzenesulfonamide (2),N-[4-(phenylsulfamoyl)phenyl]benzamide (3) and N-{4-[(3-chlorophenyl)sulfamoyl]phenylbenzamide (4) were synthesized and characterized by Infra-Red (IR), Nuclear Magnetic Resonance (NMR) and UV–visible (UV–Vis) spectra. Also Liquid Chromatographic (LCMS) and High Resolution Mass Spectrometric (HRMS) methods were used. Crystal structures of 1–4 were determined by single crystal X-ray diffraction (XRD) and their conformational and hydrogen bond (HB) network properties were examined with survey of the literature data. Compounds 1 and 2 crystallize in the same orthorhombic Pbca symmetry with equivalent molecular conformation (tilted V-shape) but showed distinct packing and hydrogen bonding models. Compounds 3 and 4 crystallize in monoclinic and triclinic crystal systems, albeit exhibiting identical molecular conformation (L-shaped). Same donor acceptor pairs both on 3 and 4 result to different kind of HB network. Thermogravimetric (TG) and differential scanning calorimetric (DSC) methods were used to evaluate thermal properties of the substances. All sulfanilamide derivatives have melting points between195–227 °C, initiation of thermal decomposition between 259–271 °C and enthalpies of fusion ΔHfusT = 38.96, 36.60, 46.23 and 44.81 kJ mol−1 were determined for 1–4, respectively. The derivatives were screened for their antibacterial and antifungal activities against various bacterial and fungal strains. It is observed that there is no significant antibacterial activity with the introduction of the benzene ring to CO–NH group or SO2–NH moiety, and none of the compounds exhibited antifungal activity.