Synthesis, Characterization and Biological Study of a New Mannich Base, 2-[(4-fluorophenyl)(phenylamino)methyl] cyclopentanone (FPC) and its Transition Metal Complexes with Cu(II), Ni(II), Co(II), Fe(II) and Zn(II)

Abstract

One pot Mannich reaction involving three components (4-fluorobenzaldehyde, aniline, cyclopentanone) was performed using ethanol as a solvent. The resulting Mannich base (FPC) was isolated and further reacted with chloride salts of Cu(II), Ni(II), Co(II), Fe(II) and Zn(II) ions to afford respective metal complexes. The structure of synthesized ligand and transition metal complexes were elucidated on the basis of IR, 1H NMR, 13C NMR, mass spectroscopy and elemental analysis. The geometries of the resulting complexes were proposed on the basis of electronic spectroscopic data and magnetic moment. The anti-enzymatic activity of the ligand and its metal complexes were carried out against urease. FPC shows potent antiurease activity with IC50 value (0.83� 0.002 �M) which is greater than standard. The Cu-complex shows excellent inhibitory action with IC50 value (16.87� 0.03 �M) while other complexes i.e Co-complex (35.59� 0.04 �M) and Ni-complex (49.93� 0.01 �M) exhibit good to moderate IC50 values as compared with control thiourea (IC50 value, 21.25� 0.15 �M). Molecular docking studies were also done on the antiurease activities of FPC and its complexes.