Used for the determination of hemoglobin adducts of aromatic amines in nonsmokers and smokers of blond- or black-tobacco cigarettes. Is an intermediate in the production of dyes, organic chemicals and aromatic azo compounds. It serves as a component of accelerators for cyanoacrylate glues. Furthermore, it acts as a bidentate Schiff base ligand through condensation with salicylaldehyde. Undergoes oxidative coupling reaction with catecholamine to form an orange water-soluble dye during flow injection-spectrophotometric determination of catecholamine drugs.