PREPARATION, CHARACTERIZATION, AND STUDY OF THE BIOLOGICAL ACTIVITY OF 5-CHLORO-8-QUINOLINOL DERIVATIVES AND ITS COORDINATION WITH THE NICKEL (II) AND DIPHOSPHINES

Abstract

Nickel complexes are effective catalysts for cross-coupling reactions between alkyl Grignard reagents and alkenyl–S and alkenyl–Se compounds. In this study, various organic compounds were prepared. Ethylnyl 2-((5-chloro-8-quinolinol)oxy) acetate compound (designated as A1) was synthesized by adding potassium carbonate to quinoline and ethyl chloroacetate. The second compound 2-((5-chloro-8- quinolinol)oxy) acetohydrazide (A2) were obtained by reacting A1with hydrazide. Complex compound A3 were obtained by reacting equimolar amounts of compound A2 with the nickel salt solution, using ethanol as the solvent. Phosphinate complexes were prepared by reacting equal moles of the A3 with the various phosphines and using ethanol as a solvent. The synthesized compounds and complexes were characterized using various spectroscopic techniques, including (FT-IR) spectroscopy, (31P-{ 1H}- 13C-NMR) spectroscopy, and C.H.N. analysis. Additionally, their melting points, purity, molar conductivity, and magnetic susceptibility were determined. The impact of some prepared compounds and complexes on the growth of two antibiotic-resistant bacterial strains, namely the Gram-negative Staphylococcus and the Gram-positive Escherichia coli, was studied. Amoxicillin was used as control antibiotics. Some of the synthesized compounds exhibited significant inhibitory activity against the tested bacterial strains. The A2 compound readily forms complexes, especially with nickel, manganese, and copper salts. The prepared compounds and complexes exhibited high stability and strength, maintaining their structure, color, and melting point even under varying laboratory temperatures between winter and summer