Synthesis of a Series of Diphenyl (Arylamino)(Pyridin-3-yl)Methylphosphonates as Potential Antimicrobial Agents

Abstract

Diphenyl 1-(arylamino)(pyridin-3-yl)methylphosphonates were obtained in high yields from the reactions of nicotinaldehyde with aromatic amines and triphenylphosphite in the presence of titanium tetrachloride (TiCl₄) as a catalyst. The structures of the synthesized compounds were confirmed by IR, ¹H NMR and mass spectral data and their purities were confirmed by elemental analyses. The synthesized α-aminophosphonates showed moderate to high antimicrobial activities against Escherichia coli (NCIM2065) as a Gram-negative bacterium, Bacillus subtilis (PC1219) and Staphylococcus aureus (ATCC25292) as Gram-positive bacteria, and Candida albicans and Schccaromycies cerevisiae as fungi, at various concentrations (10–100 μg/mL).The lethal dose of the synthesized compounds was also determined and indicated that most compounds are safe to use.

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GRAPHICAL ABSTRACT

Keywords:

• α-Aminophosphonate
• nicotinaldehyde
• minimum inhibitory concentrations
• antimicrobial properties
• lethal dose