2-Naphthylamine

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2-Naphthylamine
Skeletal formula
Ball-and-stick model
Names
Preferred IUPAC name
Naphthalen-2-amine
Other names
(Naphthalen-2-yl)amine
2-Naphthylamine
β-Naphthylamine
Identifiers
91-59-8 YesY
3D model (Jmol) Interactive image
ChEBI CHEBI:27878 YesY
ChEMBL ChEMBL278164 YesY
ChemSpider 6790 YesY
ECHA InfoCard 100.001.892
KEGG C02227 YesY
Properties
C10H9N
Molar mass 143.19 g·mol−1
Appearance White to red crystals[1]
Odor odorless[1]
Density 1.061 g/cm3
Melting point 111 to 113 °C (232 to 235 °F; 384 to 386 K)
Boiling point 306 °C (583 °F; 579 K)
miscible in hot water[1]
Vapor pressure 1 mmHg (107° C)[1]
Acidity (pKa) 3.92
Hazards
Flash point 157 °C; 315 °F; 430 K
Related compounds
Related compounds
2-Naphthol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

2-Naphthylamine is one of two isomeric aminonaphthalenes, compounds with the formula C10H7NH2. It is a colorless solid, but samples take on a reddish color in air because of oxidiation. The aromatic amine used to be used to make azo dyes. It is a known carcinogen and has largely been replaced by less toxic compounds.[2]

Preparation[edit]

2-Naphthylamine is prepared by heating 2-naphthol with ammonium zinc chloride to 200-210 °C, the Bucherer reaction. It also can be produced its acetyl derivative by heating 2-naphthol with ammonium acetate to 270-280 °C.

Reactions[edit]

It gives no color with iron(III) chloride. When reduced by sodium in boiling amyl alcohol solution, it forms tetrahydro-3-naphthylamine, which exhibits the properties of the aliphatic amines in that it is strongly alkaline in reaction, has an ammoniacal odor and cannot be diazotized.

On oxidation, it yields ortho-carboxy-hydrocinnamic acid, HO2CC6H4CH2CH2CO2H.

Numerous sulfonic acid derivatives of 2-naphthylamine are used in commerce, such as precursors to dyes.[2] Owing to the carcinogenicity of the amine, these derivatives are mainly prepared by amination of the corresponding naphthols. Of them, 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[edit]

2-Naphthylamine is found in cigarette smoke and suspected to contribute to the development of bladder cancer.[3]

It is activated in the liver but quickly deactivated by conjugation to glucuronic acid. In the bladder, glucuronidase re-activates it by deconjugation, which leads to the development of bladder cancer.

See also[edit]

References[edit]

  1. ^ a b c d e "NIOSH Pocket Guide to Chemical Hazards #0442". National Institute for Occupational Safety and Health (NIOSH). 
  2. ^ a b Gerald Booth "Naphthalene Derivatives" in Ullmann's Encyclopedia of Industrial Chemistry, 2005, Wiley-VCH, Weinheim. doi:10.1002/14356007.a17_009.
  3. ^ CDC - NIOSH Pocket Guide to Chemical Hazards