Synthesis, characterization and antimicrobial activities of oxazol-5-one derivatives
This study synthesized some oxazol-5-one derivatives, characterized these compounds and carried out in vitro antibacterial and antifungal study. This was with a view to providing more information about the microbial potential of these targeted oxazol-5-one derivatives. N-Acetylglycine, 141 was prepared by the reaction of glycine with acetyl bromide in the presence of sodium hydroxide, followed by purification via recrystallization. Various oxazol-5-one derivatives 142a-f were obtained by an intramolecular cyclodehydration of N-acetylglycine using acetic anhydride, followed by an aldol-condensation with different aromatic aldehydes with anhydrous sodium acetate as catalyst in one pot. The synthesized compounds were characterized using 1H-NMR, 13C-NMR and IR spectroscopy. The synthesized compounds were screened in vitro for antimicrobial activity, using ampicillin and streptomycin as clinical references for antibacterial activity and nystatin as reference for antifungal activity. N-Acetylglycine, 141 was obtained in a yield of about 58% while the oxazolone derivatives, 142a-f were obtained in yields of up to 39%. Compounds 141, 142a-f were screened for antimicrobial activity against bacterial and fungal strains. Among the tested compounds, compound 142e showed a better activity against Escherichia colithan ampicillin but a comparable activity with streptomycin. Against Streptococcus pneumoniae, compound 142e showed a better activity than both ampicillin and streptomycin. Compound 142e also showed the highest bactericidal concentration than other synthesized compounds against Escherichia coli,better than ampicillin, but comparable with streptomycin. None of the synthesized compounds showed any activity against the tested fungal strains. The study concluded that compound 142ewhich showed better activity than ampicillin and a comparable activity to streptomycin againstEscherichia coliandStreptococcus pneumoniae could be explored in the treatment of microbial infections caused by these organisms.