Dimethylamine

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Dimethylamine
Me2NH.svg
Dimethylamine-3D-balls.png
Names
Preferred IUPAC name
N-Methylmethanamine
Other names
(Dimethyl)amine
Identifiers
3D model (JSmol)
3DMet
605257
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.004.272 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 204-697-4
849
KEGG
MeSH dimethylamine
PubChem CID
RTECS number
  • IP8750000
UNII
UN number 1032
  • InChI=1S/C2H7N/c1-3-2/h3H,1-2H3 Yes check.svgY
    Key: ROSDSFDQCJNGOL-UHFFFAOYSA-N Yes check.svgY
  • CNC
Properties [1] [2]
(CH3)2NH
Molar mass 45.085 g·mol−1
AppearanceColorless gas
Odor Fishy, ammoniacal
Density 649.6 kg m−3 (at 25 °C)
Melting point −93.00 °C; −135.40 °F; 180.15 K
Boiling point 7 to 9 °C; 44 to 48 °F; 280 to 282 K
1.540 kg L−1
log P −0.362
Vapor pressure 170.3 kPa (at 20 °C)
310 μmol Pa−1 kg−1
Basicity (pKb)3.29
Thermochemistry
−21 to −17 kJ mol−1
Hazards
GHS labelling:
GHS-pictogram-flamme.svg GHS-pictogram-acid.svg GHS-pictogram-exclam.svg
Danger
H220, H302, H315, H318, H332, H335
P210, P261, P280, P305+P351+P338
NFPA 704 (fire diamond)
NFPA 704.svgHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 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
2
4
0
Flash point −6 °C (21 °F; 267 K) (liquid)
401 °C (754 °F; 674 K)
Explosive limits 2.8–14.4%
Lethal dose or concentration (LD, LC):
698 mg/kg (rat, oral)
316 mg/kg (mouse, oral)
240 mg/kg (rabbit, oral)
240 mg/kg (guinea pig, oral) [3]
4700 ppm (rat, 4 hr)
4540 ppm (rat, 6 hr)
7650 ppm (mouse, 2 hr) [3]
NIOSH (US health exposure limits):
PEL (Permissible)
TWA 10 ppm (18 mg/m3) [4]
REL (Recommended)
TWA 10 ppm (18 mg/m3) [4]
IDLH (Immediate danger)
500 ppm [4]
Related compounds
Related amines
Related compounds
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Yes check.svgY  verify  (what is  Yes check.svgYX mark.svgN ?)

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. [5]

Contents

Structure and synthesis

The molecule consists of a nitrogen atom with two methyl substituents and one hydrogen. Dimethylamine is a weak base and the pKa of the ammonium CH3-NH+
2-CH3 is 10.73, a value above methylamine (10.64) and trimethylamine (9.79).

Dimethylamine reacts with acids to form salts, such as dimethylamine hydrochloride, an odorless white solid with a melting point of 171.5 °C. Dimethylamine is produced by catalytic reaction of methanol and ammonia at elevated temperatures and high pressure: [6]

2 CH3OH + NH3 → (CH3)2NH + 2 H2O

Natural occurrence

Dimethylamine is found quite widely distributed in animals and plants, and is present in many foods at the level of a few mg/kg. [7]

Uses

Dimethylamine is a precursor to several industrially significant compounds. [5] [8] It reacts with carbon disulfide to give dimethyl dithiocarbamate, a precursor to zinc bis(dimethyldithiocarbamate) and other chemicals used in the sulfur vulcanization of rubber. Dimethylaminoethoxyethanol is manufactured by reacting dimethylamine and ethylene oxide. [9] Other methods are also available producing streams rich in the substance which then need to be further purified. [10] The solvents dimethylformamide and dimethylacetamide are derived from dimethylamine. It is raw material for the production of many agrichemicals and pharmaceuticals, such as dimefox and diphenhydramine, respectively. The chemical weapon tabun is derived from dimethylamine. The surfactant lauryl dimethylamine oxide is found in soaps and cleaning compounds. Unsymmetrical dimethylhydrazine, a rocket fuel, is prepared from dimethylamine. [11]

(CH3)2NH + NH2Cl → (CH3)2NNH2 ⋅ HCl

It is an attractant for boll weevils. [12]

Reactions

It is basic, in both the Lewis [13] [14] and Brønsted senses. It easily forms dimethylammonium salts upon treatment with acids. Deprotonation of dimethylamine can be effected with organolithium compounds. The resulting LiNMe2, which adopts a cluster-like structure, serves as a source of Me2N−. This lithium amide has been used to prepare volatile metal complexes such as tetrakis(dimethylamido)titanium and pentakis(dimethylamido)tantalum.

It reacts with many carbonyl compounds. Aldehydes give aminals. For example reaction of dimethylamine and formaldehyde gives bis(dimethylamino)methane: [15]

2 (CH3)2NH + CH2O → [(CH3)2N]2CH2 + H2O

It converts esters to dimethylamides.

Safety

Dimethylamine is not very toxic with the following LD50 values: 736 mg/kg (mouse, i.p.); 316 mg/kg (mouse, p.o.); 698 mg/kg (rat, p.o.); 3900 mg/kg (rat, dermal); 240 mg/kg (guinea pig or rabbit, p.o.). [16]

Although not acutely toxic, dimethylamine undergoes nitrosation to give dimethylnitrosamine, a carcinogen.

See also

Related Research Articles

Unsymmetrical dimethylhydrazine (abbreviated as UDMH; also known as 1,1-dimethylhydrazine, heptyl or Geptil) is a chemical compound with the formula H2NN(CH3)2 that is primarily used as a rocket propellant. At room temperature, UDMH is a colorless liquid, with a sharp, fishy, ammonia-like smell typical of organic amines. Samples turn yellowish on exposure to air and absorb oxygen and carbon dioxide. It is miscible with water, ethanol, and kerosene. At concentrations between 2.5% and 95% in air, its vapors are flammable. It is not sensitive to shock.

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

N,N-Dimethylaniline (DMA) is an organic chemical compound, a substituted derivative of aniline. It is a tertiary amine, featuring a dimethylamino group attached to a phenyl group. This oily liquid is colourless when pure, but commercial samples are often yellow. It is an important precursor to dyes such as crystal violet.

<span class="mw-page-title-main">1,2-Dibromoethane</span> Chemical compound

1,2-Dibromoethane, also known as ethylene dibromide (EDB), is an organobromine compound with the chemical formula C
2H
4Br
2. Although trace amounts occur naturally in the ocean, where it is probably formed by algae and kelp, substantial amounts are produced industrially. It is a dense colorless liquid with a faint, sweet odor, detectable at 10 ppm. It is a widely used and sometimes-controversial fumigant. The combustion of 1,2-dibromoethane produces hydrogen bromide gas that is significantly corrosive.

<span class="mw-page-title-main">Ethylene oxide</span> Cyclic compound (C2H4O)

Ethylene oxide is an organic compound with the formula C2H4O. It is a cyclic ether and the simplest epoxide: a three-membered ring consisting of one oxygen atom and two carbon atoms. Ethylene oxide is a colorless and flammable gas with a faintly sweet odor. Because it is a strained ring, ethylene oxide easily participates in a number of addition reactions that result in ring-opening. Ethylene oxide is isomeric with acetaldehyde and with vinyl alcohol. Ethylene oxide is industrially produced by oxidation of ethylene in the presence of a silver catalyst.

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

Ethanolamine is a naturally occurring organic chemical compound with the formula HOCH
2CH
2NH
2 or C
2H
7NO. The molecule is bifunctional, containing both a primary amine and a primary alcohol. Ethanolamine is a colorless, viscous liquid with an odor reminiscent of ammonia.

<span class="mw-page-title-main">Methylamine</span> Organic chemical compound

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.

Dimethylformamide, DMF 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.

<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.

Morpholine is an organic chemical compound having the chemical formula O(CH2CH2)2NH. This heterocycle features both amine and ether functional groups. Because of the amine, morpholine is a base; its conjugate acid is called morpholinium. For example, treating morpholine with hydrochloric acid generates the salt morpholinium chloride. It is a colorless liquid with a weak, ammonia- or fish-like odor. The naming of morpholine is attributed to Ludwig Knorr, who incorrectly believed it to be part of the structure of morphine.

<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">Isobutanol</span> Chemical compound

Isobutanol (IUPAC nomenclature: 2-methylpropan-1-ol) is an organic compound with the formula (CH3)2CHCH2OH (sometimes represented as i-BuOH). This colorless, flammable liquid with a characteristic smell is mainly used as a solvent either directly or as its esters. Its isomers are 1-butanol, 2-butanol, and tert-butanol, all of which are important industrially.

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

Diethanolamine, often abbreviated as DEA or DEOA, is an organic compound with the formula HN(CH2CH2OH)2. Pure diethanolamine is a white solid at room temperature, but its tendencies to absorb water and to supercool often results in it being found in a colorless, viscous liquid state. Diethanolamine is polyfunctional, being a secondary amine and a diol. Like other organic amines, diethanolamine acts as a weak base. Reflecting the hydrophilic character of the secondary amine and hydroxyl groups, DEA is soluble in water. Amides prepared from DEA are often also hydrophilic. In 2013, the chemical was classified by the International Agency for Research on Cancer as "possibly carcinogenic to humans" (Group 2B).

<i>o</i>-Xylene Chemical compound

o-Xylene (ortho-xylene) is an aromatic hydrocarbon with the formula C6H4(CH3)2, with two methyl substituents bonded to adjacent carbon atoms of a benzene ring (the ortho configuration). It is a constitutional isomer of m-xylene and p-xylene, the mixture being called xylene or xylenes. o-Xylene is a colourless slightly oily flammable liquid.

2-Chloroethanol (also called ethylene chlorohydrin or glycol chlorohydrin) is an organic chemical compound with the chemical formula HOCH2CH2Cl and the simplest beta-halohydrin (chlorohydrin). This colorless liquid has a pleasant ether-like odor. It is miscible with water. The molecule is bifunctional, consisting of both an alkyl chloride and an alcohol functional group.

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

Diphenylamine is an organic compound with the formula (C6H5)2NH. The compound is a derivative of aniline, consisting of an amine bound to two phenyl groups. The compound is a colorless solid, but commercial samples are often yellow due to oxidized impurities. Diphenylamine dissolves well in many common organic solvents, and is moderately soluble in water. It is used mainly for its antioxidant properties. Diphenylamine is widely used as an industrial antioxidant, dye mordant and reagent and is also employed in agriculture as a fungicide and antihelmintic.

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

Diethylamine is an organic compound with the formula (CH3CH2)2NH. It is classified as a secondary amine. It is a flammable, volatile 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">Tetramethylammonium chloride</span> Chemical compound

Tetramethylammonium chloride is one of the simplest quaternary ammonium salts, with four methyl groups tetrahedrally attached to the central N. The chemical formula (CH3)4N+Cl− is often abbreviated further as Me4N+Cl−. It is a hygroscopic colourless solid that is soluble in water and polar organic solvents. Tetramethylammonium chloride is a major industrial chemical, being used widely as a chemical reagent and also as a low-residue bactericide in such processes as hydrofracking. In the laboratory, it has fewer synthetic chemical applications than quaternary ammonium salts containing longer N-alkyl substituents, which are used extensively as phase-transfer catalysts.

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

Diethylethanolamine (DEAE) is the organic compound with the molecular formula (C2H5)2NCH2CH2OH. A colorless liquid, is used as a precursor in the production of a variety of chemical commodities such as the local anesthetic procaine.

2-[2-(Dimethylamino)ethoxy]ethanol is an organic compound with the molecular formula C6H15NO2 and is a liquid at room temperature. Dimethylaminoethoxyethanol is polyfunctional, having a tertiary amine, ether and hydroxyl functionality. Like other organic amines, it acts as a weak base.

References

  1. ↑ "Dimethylamine". NIST Chemistry WebBook. USA: National Institute of Standards and Technology. Retrieved 15 February 2022.
  2. ↑ "Dimethylamine 38931 - ≥99.0%". Aldrich. Sigma-Aldrich Co. Retrieved 15 February 2022.
  3. 1 2 "Dimethylamine". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
  4. 1 2 3 NIOSH Pocket Guide to Chemical Hazards. "#0219". National Institute for Occupational Safety and Health (NIOSH).
  5. 1 2 Van Gysel, August B.; Musin, Willy (2000). "Methylamines". Ullmann's Encyclopedia of Industrial Chemistry . Weinheim: Wiley-VCH. doi:10.1002/14356007.a16_535. ISBN   978-3527306732.
  6. ↑ Corbin D.R.; Schwarz S.; Sonnichsen G.C. (1997). "Methylamines synthesis: A review". Catalysis Today. 37 (2): 71–102. doi:10.1016/S0920-5861(97)00003-5.
  7. ↑ Neurath, G. B.; et al. (1977). "Primary and secondary amines in the human environment". Food and Cosmetics Toxicology. 15 (4): 275–282. doi:10.1016/s0015-6264(77)80197-1. PMID   590888.
  8. ↑ Ashford's Dictionary of Industrial Chemicals, 3rd edition, 2011, pages 3284-3286
  9. ↑ Frank, H., 2007. Preparation of N, N-Dimethylaminoethoxyethanol by Reacting Reacting Di-methylamine with Ethylene Oxide US Patent
  10. ↑ US8907084B2 - Process for the preparation of 2-(2-aminoethoxy) ethanol (2AEE) and morpholine with 2AEE: morpholine >3 - Google Patents
  11. ↑ Schirmann, Jean-Pierre; Bourdauducq, Paul (2001). "Hydrazine". Ullmann's Encyclopedia of Industrial Chemistry . Weinheim: Wiley-VCH. doi:10.1002/14356007.a13_177. ISBN   3-527-30673-0.
  12. ↑ The Merck Index, 10th Ed. (1983), p.470, Rahway: Merck & Co.
  13. ↑ Laurence, Christian; Le Gall, Jean-François (2010). Lewis basicity and affinity scales: data and measurement. Oxford: Wiley-Blackwell. pp. 50–51. ISBN   978-0-470-74957-9.
  14. ↑ Cramer, R. E.; Bopp, T. T. (1977). "Graphical display of the enthalpies of adduct formation for Lewis acids and bases". Journal of Chemical Education. 54: 612–613. doi:10.1021/ed054p612. The plots shown in this paper used older parameters. Improved E&C parameters are listed in ECW model.
  15. ↑ Gaudry, Michel; Jasor, Yves; Khac, Trung Bui (1979). "Regioselective Mannich Condensation with Dimethyl(Methylene)ammonium Trifluoroacetate: 1-(Dimethylamino)-4-methyl-3-pentanone". Org. Synth. 59: 153. doi:10.15227/orgsyn.059.0153.
  16. ↑ Chemical Information Profile for Dimethylamine Borane, National Toxicology Program, NIEHS, NIH (2008), p.4: http://ntp.niehs.nih.gov/ntp/htdocs/Chem_Background/ExSumPdf/DimethylamineBorane508.pdf
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