2-Naphthylamine

2-Naphthylamine is an aromatic amine. It is used to make azo dyes. It is a known human carcinogen and has largely been replaced by less toxic compounds. 2-Naphthylamine is prepared by heating 2-naphthol with ammonium zinc chloride to 200-210 °C; or in the form of its acetyl derivative by heating 2-naphthol with ammonium acetate to 270-280 °C. It forms odorless, colorless plates which melt at 111-112 °C. It gives no color with ferric chloride. When reduced by sodium in boiling amyl alcohol solution it forms alicyclic tetrahydro-3-naphthylamine, which has most of the properties of the aliphatic amines; it is strongly alkaline in reaction, has an ammoniacal odor and cannot be diazotized. On oxidation it yields ortho-carboxy-hydrocinnamic acid, HO2C•C6H4•CH2•CH2•CO2H. Numerous sulfonic acids derived from 2-naphthylamine are known. Of these, the δ-acid and Bronner's acid are of more value technically, since they combine with ortho-tetrazoditolyl to produce fine red dye-stuffs.

Role in disease
2-Naphthylamine is found in cigarette smoke and suspected to be contributory to the development of bladder cancer.