Cyclohexylamine

Summary

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.

Cyclohexylamine[1]
Names
Preferred IUPAC name
Cyclohexanamine
Other names
Aminocyclohexane
Aminohexahydrobenzene
Hexahydroaniline
Hexahydrobenzenamine
Identifiers
  • 108-91-8 checkY
3D model (JSmol)
  • Interactive image
3DMet
  • B00135
ChEBI
  • CHEBI:15773 checkY
ChEMBL
  • ChEMBL1794762
ChemSpider
  • 7677 checkY
ECHA InfoCard 100.003.300 Edit this at Wikidata
EC Number
  • 203-629-0
  • 5507
KEGG
  • C00571 checkY
  • 7965
RTECS number
  • GX0700000
UNII
  • I6GH4W7AEG checkY
  • DTXSID1023996 Edit this at Wikidata
  • InChI=1S/C6H13N/c7-6-4-2-1-3-5-6/h6H,1-5,7H2 checkY
    Key: PAFZNILMFXTMIY-UHFFFAOYSA-N checkY
  • InChI=1/C6H13N/c7-6-4-2-1-3-5-6/h6H,1-5,7H2
    Key: PAFZNILMFXTMIY-UHFFFAOYAP
  • NC1CCCCC1
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]
1.4565
Hazards
GHS labelling:
GHS02: FlammableGHS05: CorrosiveGHS07: Exclamation markGHS08: Health hazard
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)
NFPA 704 four-colored diamondHealth 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasFlammability 3: Liquids and solids that can be ignited under almost all ambient temperature conditions. Flash point between 23 and 38 °C (73 and 100 °F). E.g. gasolineInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
3
3
0
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):
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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Infobox references

It is a useful intermediate in the production of many other organic compounds (e.g. cyclamate)

Preparation edit

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.

Applications edit

 
Cyclamate, a derivative of cyclohexylamine, is a popular artificial sweetener.

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]

Toxicity edit

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]

References edit

  1. ^ Merck Index, 11th Edition, 2735.
  2. ^ a b c d e f NIOSH Pocket Guide to Chemical Hazards. "#0168". National Institute for Occupational Safety and Health (NIOSH).
  3. ^ H. K. Hall, J. Am. Chem. Soc. (1957) 79 5441.
  4. ^ a b 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.
  5. ^ Apps, E. A. (1958). Printing Ink Technology. London: Leonard Hill [Books] Limited. pp. ix.
  6. ^ The Merck Index, 10th Ed. (1983) p.392, Rahway: Merck & Co.