Diphenylamine

Diphenylamine is an organic compound with the formula (C6H5)2NH. The compound is a derivative of aniline, consisting of an amine bound to two phenyl groups. The compound is a colorless solid, but commercial samples are often yellow due to oxidized impurities. Diphenylamine dissolves well in many common organic solvents, and is moderately soluble in water. It is used mainly for its antioxidant properties. Diphenylamine is widely used as an industrial antioxidant, dye mordant and reagent and is also employed in agriculture as a fungicide and antihelmintic. Diphenylamine is an organic compound with the formula (C6H5)2NH. The compound is a derivative of aniline, consisting of an amine bound to two phenyl groups. The compound is a colorless solid, but commercial samples are often yellow due to oxidized impurities. Diphenylamine dissolves well in many common organic solvents, and is moderately soluble in water. It is used mainly for its antioxidant properties. Diphenylamine is widely used as an industrial antioxidant, dye mordant and reagent and is also employed in agriculture as a fungicide and antihelmintic. Diphenylamine is manufactured by the thermal deamination of aniline over oxide catalysts: It is a weak base, with a Kb of 10−14. With strong acids, it forms salts. For example, treatment with sulfuric acid gives the bisulfate +− as a white or yellowish powder with m.p. 123-125 °C. Diphenylamine undergoes various cyclisation reactions. With sulfur, it gives phenothiazine, a precursor to pharmaceuticals. With iodine, it undergoes dehydrogenation to give carbazole, with release of hydrogen iodide: Arylation with iodobenzene gives triphenylamine. Diphenylamine is used as a pre- or postharvest scald inhibitor for apples applied as an indoor drench treatment. Its anti-scald activity is the result of its antioxidant properties, which protect the apple skin from the oxidation products of α-farnesene during storage. Apple scald is physical injury that manifests in brown spots after fruit is removed from cold storage. In the manufacture of smokeless powder, diphenylamine is commonly used as a stabilizer, such that the gunshot residue analysis seeks to quantify traces of diphenylamine. Diphenylamine functions by binding nitrocellulose degradation products (e.g. NO, NO2, and nitric acid), preventing these degradation products from accelerating further degradation. Alkylated diphenylamines function as antioxidants in lubricants, approved for use in machines, in which contact with food is not ruled out. Alkylated diphenylamines and other derivatives are used as anti-ozonants in the manufacture of rubber products, reflecting the antioxidant nature of aniline derivatives.