Aniline

For other uses, see Aniline (disambiguation).
Not to be confused with the amino acid alanine, or annulene.
Aniline
Structural formula of aniline
Structural formula of aniline
Aniline
Aniline
Names
Preferred IUPAC name
Aniline[1]
Systematic IUPAC name
Benzenamine
Other names
Phenylamine
Aminobenzene
Benzamine
Identifiers
3D model (JSmol)
3DMet
605631
ChEBI
ChEMBL
ChemSpider
DrugBank
ECHA InfoCard 100.000.491 Edit this at Wikidata
EC Number
  • 200-539-3
2796
KEGG
RTECS number
  • BW6650000
UNII
UN number 1547
  • InChI=1S/C6H7N/c7-6-4-2-1-3-5-6/h1-5H,7H2 checkY
    Key: PAYRUJLWNCNPSJ-UHFFFAOYSA-N checkY
  • InChI=1/C6H7N/c7-6-4-2-1-3-5-6/h1-5H,7H2
    Key: PAYRUJLWNCNPSJ-UHFFFAOYAP
  • Nc1ccccc1
  • c1ccc(cc1)N
Properties
C6H5NH2
Molar mass 93.129 g·mol−1
Appearance Colorless liquid
Density 1.0297 g/mL
Melting point −6.30 °C (20.66 °F; 266.85 K)
Boiling point 184.13 °C (363.43 °F; 457.28 K)
3.6 g/(100 mL) at 20 °C
Vapor pressure 0.6 mmHg (20 °C)[2]
Acidity (pKa)
  • 4.63 (conjugate acid; H2O)[3]
−62.95·10−6 cm3/mol
1.58364
Viscosity 3.71 cP (3.71 mPa·s at 25 °C)
Thermochemistry
−3394 kJ/mol
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
 potential occupational carcinogen
GHS labelling:
GHS05: CorrosiveGHS06: ToxicGHS08: Health hazardGHS09: Environmental hazardGHS07: Exclamation mark
Danger
H301, H311, H317, H318, H331, H341, H351, H372, H400
P201, P202, P260, P261, P264, P270, P271, P272, P273, P280, P281, P301+P310, P302+P352, P304+P340, P305+P351+P338, P308+P313, P310, P311, P312, P314, P321, P322, P330, P333+P313, P361, P363, P391, P403+P233, P405, P501
NFPA 704 (fire diamond)
[5]
NFPA 704 four-colored diamondHealth 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasFlammability 2: Must be moderately heated or exposed to relatively high ambient temperature before ignition can occur. Flash point between 38 and 93 °C (100 and 200 °F). E.g. diesel fuelInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
3
2
0
Flash point 70 °C (158 °F; 343 K)
770 °C (1,420 °F; 1,040 K)
Explosive limits 1.3–11%[2]
Lethal dose or concentration (LD, LC):
195 mg/kg (dog, oral)
250 mg/kg (rat, oral)
464 mg/kg (mouse, oral)
440 mg/kg (rat, oral)
400 mg/kg (guinea pig, oral)[4]
175 ppm (mouse, 7 h)[4]
250 ppm (rat, 4 h)
180 ppm (cat, 8 h)[4]
NIOSH (US health exposure limits):
PEL (Permissible)
 TWA 5 ppm (19 mg/m3) [skin][2]
REL (Recommended)
 Ca [potential occupational carcinogen][2]
IDLH (Immediate danger)
 100 ppm[2]
Related compounds
1-Naphthylamine
2-Naphthylamine
Related compounds
 Phenylhydrazine
Nitrosobenzene
Nitrobenzene
Supplementary data page
Aniline (data page)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

Aniline (from Portuguese anil 'indigo shrub', and -ine indicating a derived substance)[6] is an organic compound with the formula C6H5NH2. Consisting of a phenyl group (−C6H5) attached to an amino group (−NH2), aniline is the simplest aromatic amine. It is an industrially significant commodity chemical, as well as a versatile starting material for fine chemical synthesis. Its main use is in the manufacture of precursors to polyurethane, dyes, and other industrial chemicals. Like most volatile amines, it has the odor of rotten fish. It ignites readily, burning with a smoky flame characteristic of aromatic compounds.[7] It is toxic to humans.

Relative to benzene, aniline is "electron-rich". It thus participates more rapidly in electrophilic aromatic substitution reactions. Likewise, it is also prone to oxidation: while freshly purified aniline is an almost colorless oil, exposure to air results in gradual darkening to yellow or red, due to the formation of strongly colored, oxidized impurities. Aniline can be diazotized to give a diazonium salt, which can then undergo various nucleophilic substitution reactions.

Like other amines, aniline is both a base (pKaH = 4.6) and a nucleophile, although less so than structurally similar aliphatic amines.

Because an early source of the benzene from which they are derived was coal tar, aniline dyes are also called coal tar dyes.

  1. ^ Nomenclature of Organic Chemistry: IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. pp. 416, 668. doi:10.1039/9781849733069-FP001. ISBN 978-0-85404-182-4. Aniline, for C6H5-NH2, is the only name for a primary amine retained as a preferred IUPAC name for which full substitution is permitted on the ring and the nitrogen atom. It is a Type 2a retained name; for the rules of substitution see P-15.1.8.2. Substitution is limited to substituent groups cited as prefixes in accordance with the seniority of functional groups explicitly expressed or implied in the functional parent compound name. The name benzenamine may be used in general nomenclature.
  2. ^ a b c d e NIOSH Pocket Guide to Chemical Hazards. "#0033". National Institute for Occupational Safety and Health (NIOSH).
  3. ^ Vollhardt, P.; Schore, Neil (2018). Organic Chemistry (8th ed.). W. H. Freeman. p. 1031. ISBN 9781319079451.
  4. ^ a b c "Aniline". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
  5. ^ "Aniline". cameochemicals.noaa.gov. US NOAA Office of Response and Restoration. Retrieved 2016-06-16.
  6. ^ "aniline | Etymology, origin and meaning of aniline by etymonline". www.etymonline.com. Retrieved 2022-02-15.
  7. ^ Cite error: The named reference Ullmann was invoked but never defined (see the help page).