659. Aniline

Nomenclature

CAS number: 62-53-3
Benzenamine; aniline oil; phenylamine; aminobenzene; aminophen; kyanol.
C6H7N; mol wt 93.13.
C 77.38%, H 7.58%, N 15.04%.

Description and references

First obtained in 1826 by Unverdorben from dry distillation of indigo. Runge found it in coal tar in 1834. Fritzsche, in 1841, prepared it from indigo and potash and gave it the name aniline. Manuf from nitrobenzene or chlorobenzene: Faith, Keyes & Clark's Industrial Chemicals, F. A. Lowenheim, M. K. Moran, Eds. (Wiley-Interscience, New York, 4th ed., 1975) pp 109-116. Procedures: A. I. Vogel, Practical Organic Chemistry (Longmans, London, 3rd ed., 1959) p 564; Gattermann-Wieland, Praxis des Organischen Chemikers (de Gruyter, Berlin, 40th ed., 1961) p 148. Brochure “Aniline” by Allied Chemical's National Aniline Division (New York, 1964) 109 pp, gives reactions and uses of aniline (877 references). Toxicity study: K. H. Jacobson, Toxicol. Appl. Pharmacol. 22, 153 (1972).

Chemical structure

Properties

Oily liquid; colorless when freshly distilled, darkens on exposure to air and light. Poisonous. Characteristic odor and burning taste; combustible; volatile with steam. d2020 1.022. bp 184-186°. Solidif 6°. Flash pt, closed cup: 169°F (76°C). nD20 1.5863. pKb 9.30. pH of 0.2 molar aq soln 8.1. One gram dissolves in 28.6 ml water, 15.7 ml boil. water; misc with alcohol, benzene, chloroform, and most other organic solvents. Combines with acids to form salts. It dissolves alkali or alkaline earth metals with evolution of hydrogen and formation of anilides, e.g., C6H5NHNa. Keep well closed and protected from light. Incompat. Oxidizers, albumin, solns of Fe, Zn, Al, acids, and alkalies. LD50 orally in rats: 0.44 g/kg (Jacobson).

Derivative

Hydrobromide.

Nomenclature

CAS number: 542-11-0
C6H7N.HBr; mol wt 174.04.
C 41.41%, H 4.63%, N 8.05%, Br 45.91%.

Properties

White to slightly reddish, crystalline powder, mp 286°. Darkens in air and light. Sol in water, alc. Protect from light.

Derivative

Hydrochloride.

Nomenclature

CAS number: 142-04-1
C6H7N.HCl; mol wt 129.59.
C 55.61%, H 6.22%, N 10.81%, Cl 27.36%.

Properties

Crystals, mp 198°. d 1.222. Darkens in air and light. Sol in about 1 part water; freely sol in alc. Protect from light.

Derivative

Hydrofluoride.

Nomenclature

CAS number: 542-13-2
C6H7N.HF; mol wt 113.13.
C 63.70%, H 7.13%, N 12.38%, F 16.79%.

Properties

Crystalline powder. Turns gray on standing. Freely sol in water; slightly sol in cold, freely in hot alc.

Derivative

Nitrate.

Nomenclature

CAS number: 542-15-4
C6H7N.HNO3; mol wt 156.14.
C 46.15%, H 5.16%, N 17.94%, O 30.74%.

Properties

Crystals, dec about 190°. d 1.36. Discolors in air and light. Sol in water, alc. Protect from light.

Derivative

Hemisulfate.

Nomenclature

CAS number: 542-16-5
C6H7N.H2SO4; mol wt 142.17.
C 50.69%, H 5.67%, N 9.85%, S 11.28%, O 22.51%.

Properties

Crystalline powder. d 1.38. Darkens on exposure to air and light. One gram dissolves in about 15 ml water; slightly sol in alc. Practically insol in ether. Protect from light.

Derivative

Acetate.

Nomenclature

CAS number: 542-14-3
C6H7N.C2H4O2; mol wt 153.18.
C 62.73%, H 7.24%, N 9.14%, O 20.89%.

Properties

Prepd from aniline and acetic acid: Vignon, Evieux, Bull. Soc. Chim. Fr. [4] 3, 1012 (1908). Colorless liquid. d 1.070-1.072. Darkens with age; gradually converted to acetanilide on standing. Misc with water, alc.

Derivative

Oxalate.

Nomenclature

CAS number: 591-43-5
(C6H7N)2.C2H2O4; mol wt 276.29.
C 60.86%, H 5.84%, N 10.14%, O 23.16%.

Properties

Prepd from aniline and oxalic acid in alc soln: Hofmann, Ann. 47, 37 (1843). Triclinic rods from water, mp 174-175°. Readily sol in water; sparingly sol in abs alc. Practically insol in ether.

Caution

Poisoning may occur from inhalation, skin penetration or ingestion. Potential symptoms of overexposure are navy blue to black lips, tongue, mucous membranes; slate gray skin; headache, nausea, vomiting, confusion, ataxia, vertigo, tinnitus, weakness, disorientation, lethargy, drowsiness; dyspnea on effort; methemoglobinemia, cyanosis, coma; tachycardia, heart blocks, arryhthmia, shock; painful micturition, hematuria, hemoglobinuria, methemoglobinuria, oliguria, renal insufficiency; cirrhosis. Direct contact may cause eye irritation. Potential occupational carcinogen. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 18; Clinical Toxicology of Commercial Products, R. E. Gosselin et al., Eds. (Williams & Wilkins, Baltimore, 5th ed., 1984) Section III, pp 31-36.

Use

Manuf dyes, medicinals, resins, varnishes, perfumes, shoe blacks; vulcanizing rubber; as solvent. Hydrochloride used in manuf of intermediates, aniline black and other dyes, in dyeing fabrics or wood black.