Cyclohexylamine
Cyclohexylamine
Chemical compound
Cyclohexylamine is an organic compound, belonging to the aliphatic amine class. It is a colorless liquid, although, like many amines, samples are often colored due to contaminants. It has a fishy odor and is miscible with water. Like other amines, it is a weak base, compared to strong bases such as NaOH, but it is a stronger base than its aromatic analog, aniline.
| Names | |
|---|---|
| Preferred IUPAC name
Cyclohexanamine | |
| Other names
Aminocyclohexane Aminohexahydrobenzene Hexahydroaniline Hexahydrobenzenamine | |
| Identifiers | |
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3D model (JSmol) |
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| 3DMet | |
| ChEBI | |
| ChEMBL | |
| ChemSpider |
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| ECHA InfoCard | 100.003.300  |
| EC Number |
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| KEGG |
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PubChem CID |
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| RTECS number |
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| UNII | |
CompTox Dashboard (EPA) |
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| Properties | |
| C6H13N | |
| Molar mass | 99.17 |
| Appearance | clear to yellowish liquid |
| Odor | strong, fishy, amine odor |
| Density | 0.8647 g/cm3 |
| Melting point | −17.7 °C (0.1 °F; 255.5 K) |
| Boiling point | 134.5 °C (274.1 °F; 407.6 K) |
| Miscible | |
| Solubility | very soluble in ethanol, oil miscible in ethers, acetone, esters, alcohol, ketones |
| Vapor pressure | 11 mmHg (20°C)[2] |
| Acidity (pKa) | 10.64[3] |
Refractive index (nD) |
1.4565 |
| Hazards | |
| GHS labelling: | |
    | |
| Danger | |
| H226, H302, H312, H314, H361 | |
| P201, P202, P210, P233, P240, P241, P242, P243, P260, P264, P270, P280, P281, P301+P312, P301+P330+P331, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P308+P313, P310, P312, P321, P322, P330, P363, P370+P378, P403+P235, P405, P501 | |
| NFPA 704 (fire diamond) | |
| Flash point | 28.6 °C (83.5 °F; 301.8 K) |
| 293 °C (559 °F; 566 K) | |
| Explosive limits | 1.5–9.4%[2] |
| Lethal dose or concentration (LD, LC): | |
LD50 (median dose) |
156 mg/kg (rat, oral) |
| NIOSH (US health exposure limits): | |
PEL (Permissible) |
none[2] |
REL (Recommended) |
TWA 10 ppm (40 mg/m3)[2] |
IDLH (Immediate danger) |
N.D.[2] |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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It is a useful intermediate in the production of many other organic compounds (e.g. cyclamate)
Cyclohexylamine is produced by two routes, the main one being the complete hydrogenation of aniline using some cobalt- or nickel-based catalysts:[4]
- C6H5NH2 + 3 H2 → C6H11NH2
It is also prepared by alkylation of ammonia using cyclohexanol.
Cyclohexylamine is used as an intermediate in synthesis of other organic compounds. It is the precursor to sulfenamide-based reagents used as accelerators for vulcanization. It is a building block for pharmaceuticals (e.g., mucolytics, analgesics, and bronchodilators). The amine itself is an effective corrosion inhibitor. The herbicide hexazinone and the anesthetic hexylcaine are derived from cyclohexylamine.[4] It has been used as a flushing aid in the printing ink industry.[5]
Cyclohexylamine has a low acute toxicity with LD50 (rat; p.o.) = 0.71 ml/kg[6] Like other amines, it is corrosive.
Cyclohexylamine is listed as an extremely hazardous substance as defined by Section 302 of the U.S. Emergency Planning and Community Right-to-Know Act. The National Institute for Occupational Safety and Health has suggested workers not be exposed to a recommended exposure limit of over 10 ppm (40 mg/m3) over an eight-hour workshift.[2]
- Merck Index, 11th Edition, 2735.
- NIOSH Pocket Guide to Chemical Hazards. "#0168". National Institute for Occupational Safety and Health (NIOSH).
- H. K. Hall, J. Am. Chem. Soc. (1957) 79 5441.
- Eller, Karsten; Henkes, Erhard; Rossbacher, Roland; Höke, Hartmut (2005). "Amines, Aliphatic". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a02_001. ISBN 978-3527306732.
- Apps, E. A. (1958). Printing Ink Technology. London: Leonard Hill [Books] Limited. pp. ix.
- The Merck Index, 10th Ed. (1983) p.392, Rahway: Merck & Co.