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 oxidation. It was formerly used to make azo dyes, but it is a known carcinogen and has largely been replaced by less toxic compounds.[2]
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| Names | |
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| Preferred IUPAC name
Naphthalen-2-amine | |
| Other names
(Naphthalen-2-yl)amine
2-Naphthylamine β-Naphthylamine | |
| Identifiers | |
3D model (JSmol)
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| 606264 | |
| ChEBI | |
| ChEMBL | |
| ChemSpider | |
| ECHA InfoCard | 100.001.892 |
| EC Number |
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| 165176 | |
| KEGG | |
PubChem CID
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| RTECS number |
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| UNII | |
| UN number | 1650 |
CompTox Dashboard (EPA)
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| Properties | |
| C10H9N | |
| Molar mass | 143.189 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 |
| -98.00·10−6 cm3/mol | |
| Hazards | |
| GHS labelling: | |
  
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| Danger | |
| H302, H350, H411 | |
| P201, P202, P264, P270, P273, P281, P301+P312, P308+P313, P330, P391, P405, P501 | |
| Flash point | 157 °C; 315 °F; 430 K |
| Related compounds | |
Related compounds
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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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Preparation
edit2-Naphthylamine is prepared by heating 2-naphthol with ammonium zinc chloride to 200-210 °C, the Bucherer reaction. Its acetyl derivative can be obtained by heating 2-naphthol with ammonium acetate to 270-280 °C.
Reactions
editIt 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.
2-Naphthylamine was previously used as a dye precursor and rubber antioxidant in the 1930s, 40s and 50s. Dupont stopped using it in the 1970s.[3]
Role in disease
edit2-Naphthylamine is found in cigarette smoke and suspected to contribute to the development of bladder cancer.[4]
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
editReferences
edit- ^ a b c d e NIOSH Pocket Guide to Chemical Hazards. "#0442". National Institute for Occupational Safety and Health (NIOSH).
- ^ a b Gerald Booth "Naphthalene Derivatives" in Ullmann's Encyclopedia of Industrial Chemistry, 2005, Wiley-VCH, Weinheim. doi:10.1002/14356007.a17_009.
- ^ Castleman, Barry (1979), Dupont's Record In Business Ethics: Another View, Washington Post, July 15th 1979
- ^ CDC - NIOSH Pocket Guide to Chemical Hazards