Abstract

In this work two series of new azoaldonitrones have been synthesized. At first,      azoaldehydes  [A₁-A₁₀] were   prepared   via  coupling reactions between the

diazonium salts of the primary aromatic amines (2-amino-5-mercapto-1,3,4-thiadiazole, 3-aminopyridine, 4-methoxyaniline, 2,4-dichloroaniline, 4-chloroaniline, 2-chloroaniline, 3-bromoaniline, 3-nitroaniline, 4-nitroaniline and benzidine, respectively) and alkaline solution of 2-hydroxybenzaldehyde as coupling reagent. Next, the resulting azoaldehydes [A₁-A₁₀] were introduced in acid-catalyzed condensation reactions with phenylhydroxylamine in absolute ethanol to obtain ten new azoaldonitrones [N₁-N₁₀] respectively. Later, treatment of azoaldehydes [A₁-A₅] with benzylhydroxylamine under the same conditions afforded five new aldonitrones [A₁₁-A₁₅] respectively. The structures of the synthesized azoaldonitrones were confirmed by (C.H.N.S) elementary analysis and the spectroscopic methods including FT-IR and ¹H NMR. The synthesized azo aldonitrones [N₁-N₁₅] were tested for their antibacterial activity against two pathogenic strains of bacteria Staphylococcus aureous (Gram-positive) and Escherichia coli (Gram-negative). The results revealed that azoaldonitrones [N₁] and [N₁₁] which are containing thiadiazole moiety showed higher activity against both strains of bacteria, while compound [N₆] appeared higher activity only against Gram positive bacteria. Moreover, most of the prepared azoaldonitrone compounds showed medium activity against Gram positive bacteria and weak activity against Gram negative bacteria