Methylamine

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Methylamine
MeNH2.svg
Ball and stick model of methylamine Methylamine-3D-balls.png
Ball and stick model of methylamine
Spacefill model of methylamine Methylamine-3D-vdW.png
Spacefill model of methylamine
Names
Pronunciation /ˌmɛθələˈmiːn/
(METH-ə-lə-MEEN), /ˌmɛθəˈlæmən/
(METH-ə-LA-mən), /məˈθɪləˌmiːn/
(mə-THIL-ə-meen) [1]
Preferred IUPAC name
Methanamine [2]
Other names
  • Aminomethane
  • Monomethylamine
Identifiers
3D model (JSmol)
3DMet
AbbreviationsMMA
741851
ChEBI
ChEMBL
ChemSpider
DrugBank
ECHA InfoCard 100.000.746 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 200-820-0
145
KEGG
MeSH methylamine
PubChem CID
RTECS number
  • PF6300000
UNII
UN number 1061
  • InChI=1S/CH5N/c1-2/h2H2,1H3 Yes check.svgY
    Key: BAVYZALUXZFZLV-UHFFFAOYSA-N Yes check.svgY
  • CN
Properties
CH3NH2
Molar mass 31.058 g·mol−1
AppearanceColorless gas
Odor Fishy, ammoniacal
Density 0.6562 g/cm3 (at 25 °C)
Melting point −93.10 °C; −135.58 °F; 180.05 K
Boiling point −6.6 to −6.0 °C; 20.0 to 21.1 °F; 266.5 to 267.1 K
1008 g/L (at 20 °C)
log P −0.472
Vapor pressure 186.10 kPa (at 20 °C)
1.4 mmol/(Pa·kg)
Acidity (pKa)10.66
Conjugate acid [CH3NH3]+ (Methylammonium)
-27.0·10−6 cm3/mol
Viscosity 230 μPa·s (at 0 °C)
1.31 D
Thermochemistry
−23.5 kJ/mol
Hazards
GHS labelling:
GHS-pictogram-flamme.svg GHS-pictogram-acid.svg GHS-pictogram-exclam.svg
Danger
H220, H315, H318, H332, H335
P210, P261, P280, P305+P351+P338, P410+P403
NFPA 704 (fire diamond)
NFPA 704.svgHealth 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasFlammability 4: Will rapidly or completely vaporize at normal atmospheric pressure and temperature, or is readily dispersed in air and will burn readily. Flash point below 23 °C (73 °F). E.g. propaneInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
3
4
0
Flash point −10 °C; 14 °F; 263 K (liquid, gas is extremely flammable) [3]
430 °C (806 °F; 703 K)
Explosive limits 4.9–20.7%
Lethal dose or concentration (LD, LC):
100 mg/kg (oral, rat)
1860 ppm (mouse, 2 hr) [3]
NIOSH (US health exposure limits):
PEL (Permissible)
TWA 10 ppm (12 mg/m3) [3]
REL (Recommended)
TWA 10 ppm (12 mg/m3) [3]
IDLH (Immediate danger)
100 ppm [3]
Safety data sheet (SDS) emdchemicals.com
Related compounds
Related alkanamines
 ethylamine, dimethylamine, trimethylamine
Related compounds
 ammonia
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
X mark.svgN  verify  (what is  Yes check.svgYX mark.svgN ?)

Methylamine is an organic compound with a formula of CH3NH2. This colorless gas is a derivative of ammonia, but with one hydrogen atom being replaced by a methyl group. It is the simplest primary amine.

Contents

Methylamine is sold as a solution in methanol, ethanol, tetrahydrofuran, or water, or as the anhydrous gas in pressurized metal containers. Industrially, methylamine is transported in its anhydrous form in pressurized railcars and tank trailers. It has a strong odor similar to rotten fish. Methylamine is used as a building block for the synthesis of numerous other commercially available compounds.

Industrial production

Methylamine has been produced industrially since the 1920s (originally by Commercial Solvents Corporation for dehairing of animal skins). [4] This was made possible by Kazimierz Smoleński  [ pl ] and his wife Eugenia who discovered amination of alcohols, including methanol, on alumina or kaolin catalyst after the WWI, filed two patent applications in 1919 [5] and published an article in 1921. [4] [6]

It is now prepared commercially by the reaction of ammonia with methanol in the presence of an aluminosilicate catalyst. Dimethylamine and trimethylamine are co-produced; the reaction kinetics and reactant ratios determine the ratio of the three products. The product most favored by the reaction kinetics is trimethylamine. [4]

CH3OH + NH3 → CH3NH2 + H2O

In this way, an estimated 115,000 tons were produced in 2005. [7]

Laboratory methods

Methylamine was first prepared in 1849 by Charles-Adolphe Wurtz via the hydrolysis of methyl isocyanate and related compounds. [7] [8] An example of this process includes the use of the Hofmann rearrangement, to yield methylamine from acetamide and bromine. [9] [10]

In the laboratory, methylamine hydrochloride is readily prepared by various other methods. One method entails treating formaldehyde with ammonium chloride. [11]

[NH4]Cl + CH2O → [CH2=NH2]Cl + H2O
[CH2=NH2]Cl + CH2O + H2O → [CH3NH3]Cl + HCOOH

The colorless hydrochloride salt can be converted to an amine by the addition of a strong base, such as sodium hydroxide (NaOH):

[CH3NH3]Cl + NaOH → CH3NH2 + NaCl + H2O

Another method entails reducing nitromethane with zinc and hydrochloric acid. [12]

Another method of methylamine production is spontaneous decarboxylation of glycine with a strong base in water.[ citation needed ]

Reactivity and applications

Methylamine is a good nucleophile as it is an unhindered amine. [13] As an amine it is considered a weak base. Its use in organic chemistry is pervasive. Some reactions involving simple reagents include: with phosgene to methyl isocyanate, with carbon disulfide and sodium hydroxide to the sodium methyldithiocarbamate, with chloroform and base to methyl isocyanide and with ethylene oxide to methylethanolamines. Liquid methylamine has solvent properties analogous to those of liquid ammonia. [14]

Representative commercially significant chemicals produced from methylamine include the pharmaceuticals ephedrine and theophylline, the pesticides carbofuran, carbaryl, and metham sodium, and the solvents N-methylformamide and N-methylpyrrolidone. The preparation of some surfactants and photographic developers require methylamine as a building block. [7]

Biological chemistry

Methylamine arises as a result of putrefaction and is a substrate for methanogenesis. [15]

Additionally, methylamine is produced during PADI4-dependent arginine demethylation. [16]

Safety

The LD50 (mouse, s.c.) is 2.5 g/kg. [17]

The Occupational Safety and Health Administration (OSHA) and National Institute for Occupational Safety and Health (NIOSH) have set occupational exposure limits at 10 ppm or 12 mg/m3 over an eight-hour time-weighted average. [18]

Regulation

In the United States, methylamine is controlled as a List 1 precursor chemical by the Drug Enforcement Administration [19] due to its use in the illicit production of methamphetamine. [20]

Fictional characters Walter White and Jesse Pinkman use methylamine as part of a process to synthesize methamphetamine in the AMC series Breaking Bad . [21] [22]

See also

Related Research Articles

<span class="mw-page-title-main">Amine</span> Chemical compounds and groups containing nitrogen with a lone pair (:N)

In chemistry, amines are compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are formally derivatives of ammonia, wherein one or more hydrogen atoms have been replaced by a substituent such as an alkyl or aryl group. Important amines include amino acids, biogenic amines, trimethylamine, and aniline. Inorganic derivatives of ammonia are also called amines, such as monochloramine.

<span class="mw-page-title-main">Isocyanate</span> Chemical group (–N=C=O)

In organic chemistry, isocyanate is the functional group with the formula R−N=C=O. Organic compounds that contain an isocyanate group are referred to as isocyanates. An organic compound with two isocyanate groups is known as a diisocyanate. Diisocyanates are manufactured for the production of polyurethanes, a class of polymers.

<span class="mw-page-title-main">Methyl isocyanate</span> Chemical compound

Methyl isocyanate (MIC) is an organic compound with the molecular formula CH3NCO. Synonyms are isocyanatomethane and methyl carbylamine. Methyl isocyanate is an intermediate chemical in the production of carbamate pesticides (such as carbaryl, carbofuran, methomyl, and aldicarb). It has also been used in the production of rubbers and adhesives. As an extremely toxic and irritating compound, it is very hazardous to human health. MIC was the principal toxicant involved in the Bhopal gas disaster, which short-term killed 4,000–8,000 people and caused permanent injury and premature deaths to tens of thousands more. It is also a very potent lachrymatory agent.

Chloromethane, also called methyl chloride, Refrigerant-40, R-40 or HCC 40, is an organic compound with the chemical formula CH3Cl. One of the haloalkanes, it is a colorless, sweet-smelling, flammable gas. Methyl chloride is a crucial reagent in industrial chemistry, although it is rarely present in consumer products, and was formerly utilized as a refrigerant. Most chloromethane is biogenic.

<span class="mw-page-title-main">Methyl acetate</span> Chemical compound

Methyl acetate, also known as MeOAc, acetic acid methyl ester or methyl ethanoate, is a carboxylate ester with the formula CH3COOCH3. It is a flammable liquid with a characteristically pleasant smell reminiscent of some glues and nail polish removers. Methyl acetate is occasionally used as a solvent, being weakly polar and lipophilic, but its close relative ethyl acetate is a more common solvent being less toxic and less soluble in water. Methyl acetate has a solubility of 25% in water at room temperature. At elevated temperature its solubility in water is much higher. Methyl acetate is not stable in the presence of strong aqueous bases or aqueous acids. Methyl acetate is not considered a VOC in the USA.

<span class="mw-page-title-main">Formamide</span> Chemical compound

Formamide is an amide derived from formic acid. It is a colorless liquid which is miscible with water and has an ammonia-like odor. It is chemical feedstock for the manufacture of sulfa drugs and other pharmaceuticals, herbicides and pesticides, and in the manufacture of hydrocyanic acid. It has been used as a softener for paper and fiber. It is a solvent for many ionic compounds. It has also been used as a solvent for resins and plasticizers. Some astrobiologists suggest that it may be an alternative to water as the main solvent in other forms of life.

Dimethylformamide is an organic compound with the chemical formula HCON(CH3)2. Its structure is HC(=O)−N(−CH3)2. Commonly abbreviated as DMF, this colourless liquid is miscible with water and the majority of organic liquids. DMF is a common solvent for chemical reactions. Dimethylformamide is odorless, but technical-grade or degraded samples often have a fishy smell due to impurity of dimethylamine. Dimethylamine degradation impurities can be removed by sparging samples with an inert gas such as argon or by sonicating the samples under reduced pressure. As its name indicates, it is structurally related to formamide, having two methyl groups in the place of the two hydrogens. DMF is a polar (hydrophilic) aprotic solvent with a high boiling point. It facilitates reactions that follow polar mechanisms, such as SN2 reactions.

The Hofmann rearrangement is the organic reaction of a primary amide to a primary amine with one less carbon atom. The reaction involves oxidation of the nitrogen followed by rearrangement of the carbonyl and nitrogen to give an isocyanate intermediate. The reaction can form a wide range of products, including alkyl and aryl amines.

<span class="mw-page-title-main">Trimethylamine</span> Chemical compound responsible for rotten fish odor

Trimethylamine (TMA) is an organic compound with the formula N(CH3)3. It is a trimethylated derivative of ammonia. TMA is widely used in industry. At higher concentrations it has an ammonia-like odor, and can cause necrosis of mucous membranes on contact. At lower concentrations, it has a "fishy" odor, the odor associated with rotting fish.

<span class="mw-page-title-main">Phosphorus trichloride</span> Chemical compound

Phosphorus trichloride is an inorganic compound with the chemical formula PCl3. A colorless liquid when pure, it is an important industrial chemical, being used for the manufacture of phosphites and other organophosphorus compounds. It is toxic and reacts readily with water to release hydrogen chloride.

Triethylamine is the chemical compound with the formula N(CH2CH3)3, commonly abbreviated Et3N. It is also abbreviated TEA, yet this abbreviation must be used carefully to avoid confusion with triethanolamine or tetraethylammonium, for which TEA is also a common abbreviation. It is a colourless volatile liquid with a strong fishy odor reminiscent of ammonia. Like diisopropylethylamine (Hünig's base), triethylamine is commonly employed in organic synthesis, usually as a base.

<span class="mw-page-title-main">Methyl methacrylate</span> Chemical compound

Methyl methacrylate (MMA) is an organic compound with the formula CH2=C(CH3)COOCH3. This colorless liquid, the methyl ester of methacrylic acid (MAA), is a monomer produced on a large scale for the production of poly(methyl methacrylate) (PMMA).

<span class="mw-page-title-main">Dimethyl sulfate</span> Chemical compound

Dimethyl sulfate (DMS) is a chemical compound with formula (CH3O)2SO2. As the diester of methanol and sulfuric acid, its formula is often written as (CH3)2SO4 or Me2SO4, where CH3 or Me is methyl. Me2SO4 is mainly used as a methylating agent in organic synthesis.

<span class="mw-page-title-main">Dimethylacetamide</span> Chemical compound

Dimethylacetamide (DMAc or DMA) is the organic compound with the formula CH3C(O)N(CH3)2. This colorless, water-miscible, high-boiling liquid is commonly used as a polar solvent in organic synthesis. DMA is miscible with most other solvents, although it is poorly soluble in aliphatic hydrocarbons.

<span class="mw-page-title-main">Dimethylamine</span> Chemical compound

Dimethylamine is an organic compound with the formula (CH3)2NH. This secondary amine is a colorless, flammable gas with an ammonia-like odor. Dimethylamine is commonly encountered commercially as a solution in water at concentrations up to around 40%. An estimated 270,000 tons were produced in 2005.

<span class="mw-page-title-main">Ethylamine</span> Chemical compound

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.

<span class="mw-page-title-main">Diethylamine</span> Chemical compound

Diethylamine is an organic compound with the formula (CH3CH2)2NH. It is a secondary amine. It is a flammable, weakly alkaline liquid that is miscible with most solvents. It is a colorless liquid, but commercial samples often appear brown due to impurities. It has a strong ammonia-like odor.

<i>n</i>-Butylamine Chemical compound

n-Butylamine is an organic compound (specifically, an amine) with the formula CH3(CH2)3NH2. This colourless liquid is one of the four isomeric amines of butane, the others being sec-butylamine, tert-butylamine, and isobutylamine. It is a liquid having the fishy, ammonia-like odor common to amines. The liquid acquires a yellow color upon storage in air. It is soluble in all organic solvents. Its vapours are heavier than air and it produces toxic oxides of nitrogen during combustion.

<span class="mw-page-title-main">1-Methylimidazole</span> Chemical compound

1-Methylimidazole or N-methylimidazole is an aromatic heterocyclic organic compound with the formula CH3C3H3N2. It is a colourless liquid that is used as a specialty solvent, a base, and as a precursor to some ionic liquids. It is a fundamental nitrogen heterocycle and as such mimics for various nucleoside bases as well as histidine and histamine.

<span class="mw-page-title-main">Methoxyamine</span> Chemical compound

Methoxyamine is the organic compound with the formula CH3ONH2. Also called O-methylhydroxylamine, it is a colourless volatile liquid that is soluble in polar organic solvent and in water. It is a derivative of hydroxylamine with the hydroxyl hydrogen replaced by a methyl group. Alternatively, it can be viewed as a derivative of methanol with the hydroxyl hydrogen replaced by an amino group. It is an isomer of N-methylhydroxylamine and aminomethanol. It decomposes in an exothermic reaction (-56 kJ/mol) to methane and azanone unless stored as a hydrochloride salt.

References

  1. ↑ "Methylamine Definition & Meaning" . Retrieved 22 April 2022.
  2. ↑ Nomenclature of Organic Chemistry: IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. p. 670. doi:10.1039/9781849733069-00648. ISBN   978-0-85404-182-4.
  3. 1 2 3 4 5 NIOSH Pocket Guide to Chemical Hazards. "#0398". National Institute for Occupational Safety and Health (NIOSH).
  4. 1 2 3 Corbin D.R.; Schwarz S.; Sonnichsen G.C. (1997). "Methylamines synthesis: A review". Catalysis Today. 37 (24): 71–102. doi:10.1016/S0920-5861(97)00003-5.
  5. ↑ PLapplication 90B1 , PLapplication 91B1 , https://uprp.gov.pl/sites/default/files/2019-12/KWARTALNIK_100_lat_wydanie_specjalne.pdf
  6. ↑ Not Available (1922). Chemical Abstracts (1922) Vol.16, No.18.
  7. 1 2 3 Karsten Eller, Erhard Henkes, Roland Rossbacher, Hartmut Höke "Amines, Aliphatic" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005. doi : 10.1002/14356007.a02_001
  8. ↑ Charles-Adolphe Wurtz (1849) "Sur une série d'alcalis organiques homologues avec l'ammoniaque" (On a series of homologous organic alkalis containing ammonia), Comptes rendus … , 28 : 223-226. Note: Wurtz's empirical formula for methylamine is incorrect because chemists in that era used an incorrect atomic mass for carbon (6 instead of 12).
  9. ↑ Mann, F. G.; Saunders, B. C. (1960). Practical Organic Chemistry (4th ed.). London: Longman. p. 128. ISBN   9780582444072.
  10. ↑ Cohen, Julius (1900). Practical Organic Chemistry (2nd ed.). London: Macmillan and Co., Limited. p.  72.
  11. ↑ Marvel, C. S.; Jenkins, R. L. (1941). "Methylamine Hydrochloride". Organic Syntheses ; Collected Volumes, vol. 1, p. 347.
  12. ↑ Gatterman, Ludwig & Wieland, Heinrich (1937). Laboratory Methods of Organic Chemistry. Edinburgh, UK: R & R Clark, Limited. pp. 157–158.
  13. ↑ Peter Scott, ed. (13 October 2009). Linker Strategies in Solid-Phase Organic Synthesis. John Wiley & Sons. p. 80. ISBN   9780470749050. ...an unhindered amine such as methylamine
  14. ↑ Debacker, Marc G.; Mkadmi, El Bachir; Sauvage, François X.; Lelieur, Jean-Pierre; Wagner, Michael J.; Concepcion, Rosario; Kim, Jineun; McMills, Lauren E. H.; Dye, James L. (1996). "The Lithium−Sodium−Methylamine System: Does a Low-Melting Sodide Become a Liquid Metal?". Journal of the American Chemical Society. 118 (8): 1997. doi:10.1021/ja952634p.
  15. ↑ Thauer, R. K. (1998). "Biochemistry of methanogenesis: A tribute to Marjory Stephenson:1998 Marjory Stephenson Prize Lecture". Microbiology. 144 (9): 2377–406. doi: 10.1099/00221287-144-9-2377 . PMID   9782487.
  16. ↑ Ng, SS; Yue, WW; Oppermann, U; Klose, RJ (February 2009). "Dynamic protein methylation in chromatin biology". Cellular and Molecular Life Sciences. 66 (3): 407–22. doi:10.1007/s00018-008-8303-z. PMC   2794343 . PMID   18923809.
  17. ↑ The Merck Index, 10th Ed. (1983), p.864, Rahway: Merck & Co.
  18. ↑ CDC - NIOSH Pocket Guide to Chemical Hazards
  19. ↑ Title 21 Code of Federal Regulations
  20. ↑ Frank, R. S. (1983). "The Clandestine Drug Laboratory Situation in the United States". Journal of Forensic Sciences. 28 (1): 18–31. doi:10.1520/JFS12235J. PMID   6680736.
  21. ↑ Matthews, Dylan (15 August 2013). "Here's what 'Breaking Bad' gets right, and wrong, about the meth business". Washington Post . Archived from the original on 3 February 2023.
  22. ↑ Harnisch, Falk; Salthammer, Tunga. "The Chemistry of Breaking Bad". Chemistry Views. Chemistry Europe. Archived from the original on 8 February 2024.
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