Ethylamine - Misplaced Pages

Ethylamine, also known as ethanamine, is an organic compound with the formula CH₃CH₂NH₂. This colourless gas has a strong ammonia-like odor. It condenses just below room temperature to a liquid miscible with virtually all solvents. It is a nucleophilic base, as is typical for amines. Ethylamine is widely used in chemical industry and organic synthesis. It is a DEA list I chemical by 21 CFR § 1310.02.

Synthesis

Ethylamine is produced on a large scale by two processes. Most commonly ethanol and ammonia are combined in the presence of an oxide catalyst:

CH₃CH₂OH + NH₃ → CH₃CH₂NH₂ + H₂O

In this reaction, ethylamine is coproduced together with diethylamine and triethylamine. In aggregate, approximately 80M kilograms/year of these three amines are produced industrially. It is also produced by reductive amination of acetaldehyde.

CH₃CHO + NH₃ + H₂ → CH₃CH₂NH₂ + H₂O

Ethylamine can be prepared by several other routes, but these are not economical. Ethylene and ammonia combine to give ethylamine in the presence of a sodium amide or related basic catalysts.

H₂C=CH₂ + NH₃ → CH₃CH₂NH₂

Hydrogenation of acetonitrile, acetamide, and nitroethane affords ethylamine. These reactions can be effected stoichiometrically using lithium aluminium hydride. In another route, ethylamine can be synthesized via nucleophilic substitution of a haloethane (such as chloroethane or bromoethane) with ammonia, utilizing a strong base such as potassium hydroxide. This method affords significant amounts of byproducts, including diethylamine and triethylamine.

CH₃CH₂Cl + NH₃ + KOH → CH₃CH₂NH₂ + KCl + H₂O

Ethylamine is also produced naturally in the cosmos; it is a component of interstellar gases.

Reactions

Like other simple aliphatic amines, ethylamine is a weak base: the pK_a of has been determined to be 10.8

Ethylamine undergoes the reactions anticipated for a primary alkyl amine, such as acylation and protonation. Reaction with sulfuryl chloride followed by oxidation of the sulfonamide give diethyldiazene, EtN=NEt. Ethylamine may be oxidized using a strong oxidizer such as potassium permanganate to form acetaldehyde.

Ethylamine like some other small primary amines is a good solvent for lithium metal, giving the ion and the solvated electron. Such solutions are used for the reduction of unsaturated organic compounds, such as naphthalenes and alkynes.

Applications

Ethylamine is a precursor to many herbicides including atrazine and simazine. It is found in rubber products as well.

Ethylamine is used as a precursor chemical along with benzonitrile (as opposed to o-chlorobenzonitrile and methylamine in ketamine synthesis) in the clandestine synthesis of cyclidine dissociative anesthetic agents (the analogue of ketamine which is missing the 2-chloro group on the phenyl ring, and its N-ethyl analog) which are closely related to the well known anesthetic agent ketamine and the recreational drug phencyclidine and have been detected on the black market, being marketed for use as a recreational hallucinogen and tranquilizer. This produces a cyclidine with the same mechanism of action as ketamine (NMDA receptor antagonism) but with a much greater potency at the PCP binding site, a longer half-life, and significantly more prominent parasympathomimetic effects.

References

Merck Index, 12th Edition, 3808.
^ NIOSH Pocket Guide to Chemical Hazards. "#0263". National Institute for Occupational Safety and Health (NIOSH).
^ "Ethylamine". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
^ Karsten Eller, Erhard Henkes, Roland Rossbacher, Hartmut Höke, "Amines, Aliphatic" Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005.doi:10.1002/14356007.a02_001
Ulrich Steinbrenner, Frank Funke, Ralf Böhling, Method and device for producing ethylamine and butylamine Archived 2012-09-12 at archive.today, United States Patent 7161039.
Nucleophilic substitution, Chloroethane & Ammonia Archived 2008-05-28 at the Wayback Machine, St Peter's School
NRAO, "Discoveries Suggest Icy Cosmic Start for Amino Acids and DNA Ingredients", Feb 28 2013
Wilson and Gisvold's Textbook of Organic Medicinal and Pharmaceutical Chemistry, 9th Ed. (1991), (J. N. Delgado and W. A. Remers, Eds.) p.878, Philadelphia: Lippincott and 10.63.
H. K. Hall, Jr. (1957). "Correlation of the Base Strengths of Amines". J. Am. Chem. Soc. 79 (20): 5441–5444. doi:10.1021/ja01577a030.
"AZOETHANE". Organic Syntheses. 52: 11. 1972. doi:10.15227/orgsyn.052.0011.
Kaiser, E. M.; Benkeser R. A. Δ9,10-Octalin Archived 2007-09-30 at the Wayback Machine, Organic Syntheses, Collected Volume 6, p.852 (1988)
"World Health Organization Critical Review Report of Ketamine, 34th ECDD 2006/4.3" (PDF).

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