Medicinal Chemistry

Complex of Co(II) with heterocyclic ligand [2-imino-3-(2-hydroxyphenyl)-1-oxazolodin-4-one] has been synthesized and characterized with the help of elemental analysis, magnetic, 1H-NMR, 13C-NMR, IR and electronic spectral data. IR spectra exhibit the coordination of the ligands to the metal ion through deprotonated phenolic oxygen and heterocyclic nitrogen. All these studies reveal square planar geometry of Co (II) complexes. Synthesized compounds have also been screened against some micro-organisms viz. Escherichia coli, S. aureus, Aspergillus niger and R. bataticola by ‘paper disc’ techn ique. It has been observed that the antimicrobial activities of metal complexes are higher than that of the free ligands.

With an intention to develop potent antimicrobial agents from the source of benzimidazole- 1,3,4-oxadiazole combined heterocyclic derivatives, novel 6-Chloro-2-(2-(5-(substituted phenyl)-1,3,4-oxadiazol-2-yl)ethyl)- 1H-benzo[d]imidazole derivatives were synthesized using condensation reaction of 3-(6-chloro-1H-benzo[d] imidazol-2-yl)propane hydrazide and benzoic acids as key step in presence of POCl3. All newly synthesized target compounds (4a-4n) were characterized by 1H NMR, Mass and IR spectral studies and were screened for their antibacterial activity with two bacterial pathogens (Gram positive: Bacillus subtilis, Gram negative: Escherichia coli) which confirmed that compounds 4a, 4b, 4d, 4g, 4h and 4n have potent activity against B. subtilis as compare with gentamicin at concentration 500 μg/mL. We hope that this study may helpful for further optimization in finding of lead antimicrobial from the origin of benzimidazole linked oxadiazole derivatives.