Synthesis of new azo compounds based on 4-aminosalicylic acid and study anti-corrosive activity

Abstract

New azo dyes were prepared from 4-amino-2-hydroxy-benzoic acid in two steps; the first step includes preparation the diazonium salt. Then, diazonium compound coupled with different aromatic compounds containing donating groups (orcinol, 2,6-dimethylphenol, hydroquinone, catechol, 1,2,4-triazole, 2-methyl-naphthol and 4-toluidine, respectively). The physical properties of synthesized compounds were studied like melting point and solubility. The target molecules were characterized using FTIR, NMR and CHNS techniques. The activity of the compounds 1, 3 and 5 as anticorrosion on carbon steel in 0.5 M HCl solution was studied using weight loss method at different times and two concentrations (0.003 M, 0.005 M) of inhibitors at 298 K. Compound 5 showed more inhibition efficiency and less weight loss at different concentration in comparison with compound 1 and compound 3.

KEY WORDS: Azo dye, 4-Aminosalicylic acid, Diazonium salt, Anti-corrosion

Bull. Chem. Soc. Ethiop. 2024, 38(2), 473-479.                                                            

DOI: https://dx.doi.org/10.4314/bcse.v38i2.14