Synthesis, characterization and biological evaluation of schiff base (N-4-(thiophene-2-yl-methyleneamino)-2,6-dimethylpyrimidine-4-yl)benzenesulfonamide and its complexes with Cu(II), Ni(II), Co(II), Fe(II), Mn(II), Zn(II) ions

Abstract

Two step synthesis of Schiff base ligand and its transition metal complexes was done by condensation reaction. In first step, the drug and aldehyde in equimolar ratio were refluxed for one hour at pH 8-9 in order to get Schiff base ligand. In second step, ligand and metal salts were refluxed for 2 hour. The ligand and Cu(II), Ni(II), Co(II), Fe(II), Mn(II), Zn(II) complexes were characterized by using different instruments like FT-IR, 1H-NMR, 13C-NMR, Mass, Atomic absorption spectrometer, Elemental analyzer, UV-visible spectrophotometer, Evans balance, Conductivitymeter and Thermogravimeter. In vitro antibacterial, antifungal and anti-inflammatory activities were also studied. The synthesized ligand and transition metal complexes were tested against Escherichia coli, Enterobacter aerogenes, Staphylococcus aureus, Bacillus pumilus, Klebsiella oxytoca, Clostridium butyrium, Mucor and Aspergillus niger. These studies demonstrated the enhanced activity of metal complexes against reported bacterial and fungal strains when compared with free Schiff base ligand. The Cu(II) complex recognized as anti-inflammatory agent while the parent drug showed no activity.