Dimethylaniline

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N,N-Dimethylaniline
Dimethylaniline skeletal.svg
Dimethylaniline-3D-balls-2.png
Names
Preferred IUPAC name
N,N-Dimethylaniline
Other names
DMA
Dimethylaminobenzene
N,N-Dimethylbenzeneamine
N,N-Dimethylphenylamine
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.004.085 OOjs UI icon edit-ltr-progressive.svg
KEGG
PubChem CID
UNII
  • InChI=1S/C8H11N/c1-9(2)8-6-4-3-5-7-8/h3-7H,1-2H3 Yes check.svgY
    Key: JLTDJTHDQAWBAV-UHFFFAOYSA-N Yes check.svgY
  • CN(C)c1ccccc1
Properties
C8H11N
Molar mass 121.183 g·mol−1
AppearanceColorless liquid
Odor amine-like
Density 0.956 g/mL
Melting point 2 °C (36 °F; 275 K)
Boiling point 194 °C (381 °F; 467 K)
2% (20°C) [1]
Vapor pressure 1 mmHg (20°C) [1]
-89.66·10−6 cm3/mol
Hazards
Flash point 63 °C (145 °F; 336 K)
Lethal dose or concentration (LD, LC):
1410 mg/kg (rat, oral) [2]
50 ppm (rat, 4 hr) [2]
NIOSH (US health exposure limits):
PEL (Permissible)
TWA 5 ppm (25 mg/m3) [skin] [1]
REL (Recommended)
TWA 5 ppm (25 mg/m3) ST 10 ppm (50 mg/m3) [skin] [1]
IDLH (Immediate danger)
100 ppm [1]
Safety data sheet (SDS) External MSDS
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 ?)

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.

Contents

Preparation and reactions

DMA was first reported in 1850 by the German chemist A. W. Hofmann, who prepared it by heating aniline and iodomethane: [3] [4]

C6H5NH2 + 2 CH3I → C6H5N(CH3)2 + 2 HI

DMA is produced industrially by alkylation of aniline with methanol in the presence of an acid catalyst: [5]

C6H5NH2 + 2 CH3OH → C6H5N(CH3)2 + 2 H2O

Similarly, it is also prepared using dimethyl ether as the methylating agent.

Dimethylaniline undergoes many of the reactions expected for an aniline, being weakly basic and reactive toward electrophiles. For example, it is nitrated to produce tetryl, a derivative with four nitro groups which was once used as explosive. It is lithiated with butyllithium. Methylating agents attack the amine to give the quaternary ammonium salt: [6]

C6H5N(CH3)2 + (CH3O)2SO2 → C6H5N(CH3)3CH3OSO3

Diethylaniline and dimethylaniline are both used as acid-absorbing bases.

Applications

DMA is a key precursor to commercially important triarylmethane dyes such as malachite green and crystal violet. [7] DMA serves as a promoter in the curing of polyester and vinyl ester resins. [8] DMA is also used as a precursor to other organic compounds. A study of the in vitro metabolism of N,N-dimethylaniline using guinea pig and rabbit preparations and GLC techniques has confirmed N-demethylation and N-oxidation as metabolic pathways, and has also established ring hydroxylation as a metabolic route. [9]

Related Research Articles

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Acridine is an organic compound and a nitrogen heterocycle with the formula C13H9N. Acridines are substituted derivatives of the parent ring. It is a planar molecule that is structurally related to anthracene with one of the central CH groups replaced by nitrogen. Like the related molecules pyridine and quinoline, acridine is mildly basic. It is an almost colorless solid, which crystallizes in needles. There are few commercial applications of acridines; at one time acridine dyes were popular, but they are now relegated to niche applications, such as with acridine orange. The name is a reference to the acrid odour and acrid skin-irritating effect of the compound.

<span class="mw-page-title-main">Aniline</span> Organic compound (C₆H₅NH₂); simplest aromatic amine

Aniline is an organic compound with the formula C6H5NH2. Consisting of a phenyl group attached to an amino group, 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. It is toxic to humans.

Mesitylene or 1,3,5-trimethylbenzene is a derivative of benzene with three methyl substituents positioned symmetrically around the ring. The other two isomeric trimethylbenzenes are 1,2,4-trimethylbenzene (pseudocumene) and 1,2,3-trimethylbenzene (hemimellitene). All three compounds have the formula C6H3(CH3)3, which is commonly abbreviated C6H3Me3. Mesitylene is a colorless liquid with sweet aromatic odor. It is a component of coal tar, which is its traditional source. It is a precursor to diverse fine chemicals. The mesityl group (Mes) is a substituent with the formula C6H2Me3 and is found in various other compounds.

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

Phthalic anhydride is the organic compound with the formula C6H4(CO)2O. It is the anhydride of phthalic acid. Phthalic anhydride is a principal commercial form of phthalic acid. It was the first anhydride of a dicarboxylic acid to be used commercially. This white solid is an important industrial chemical, especially for the large-scale production of plasticizers for plastics. In 2000, the worldwide production volume was estimated to be about 3 million tonnes per year.

<i>p</i>-Phenylenediamine Chemical compound

p-Phenylenediamine (PPD) is an organic compound with the formula C6H4(NH2)2. This derivative of aniline is a white solid, but samples can darken due to air oxidation. It is mainly used as a component of engineering polymers and composites like kevlar. It is also an ingredient in hair dyes and is occasionally used as a substitute for henna.

<span class="mw-page-title-main">Azo compound</span> Organic compounds with a diazenyl group (–N=N–)

Azo compounds are organic compounds bearing the functional group diazenyl.

There are three isomers of toluidine, which are organic compounds. These isomers are o-toluidine, m-toluidine, and p-toluidine, with the prefixed letter abbreviating, respectively, ortho; meta; and para. All three are aryl amines whose chemical structures are similar to aniline except that a methyl group is substituted onto the benzene ring. The difference between these three isomers is the position where the methyl group (–CH3) is bonded to the ring relative to the amino functional group (–NH2); see illustration of the chemical structures below.

The Ullmann condensation or Ullmann-type reaction is the copper-promoted conversion of aryl halides to aryl ethers, aryl thioethers, aryl nitriles, and aryl amines. These reactions are examples of cross-coupling reactions.

<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">Trimethyl phosphate</span> Chemical compound

Trimethyl phosphate is the trimethyl ester of phosphoric acid. It is a colourless, nonvolatile liquid. It has some specialized uses in the production of other compounds.

<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">Triphenylmethanol</span> Chemical compound

Triphenylmethanol is an organic compound. It is a white crystalline solid that is insoluble in water and petroleum ether, but well soluble in ethanol, diethyl ether, and benzene. In strongly acidic solutions, it produces an intensely yellow color, due to the formation of a stable "trityl" carbocation. Many derivatives of triphenylmethanol are important dyes.

<span class="mw-page-title-main">Hofmann–Martius rearrangement</span>

The Hofmann–Martius rearrangement in organic chemistry is a rearrangement reaction converting an N-alkylated aniline to the corresponding ortho and / or para aryl-alkylated aniline. The reaction requires heat, and the catalyst is an acid like hydrochloric acid.

Diisopropylamine is a secondary amine with the chemical formula (Me2CH)2NH (Me = methyl). Diisopropylamine is a colorless liquid with an ammonia-like odor. Its lithium derivative, lithium diisopropylamide, known as LDA is a widely used reagent.

<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.

<i>para</i>-Cresidine Chemical compound

para-Cresidine is an organic compound with the formula CH3OC6H3(CH3)NH2. It is a white solid that is soluble in organic solvents. The compound features both amine and methoxy functional groups. It is used as an intermediate in preparation of dyes and pigments.

<span class="mw-page-title-main">2,4,6-Trimethylaniline</span> Chemical compound

2,4,6-Trimethylaniline is an organic compound with formula (CH3)3C6H2NH2. It is an aromatic amine that is of commercial interest as a precursor to dyes. It is prepared by selective monoamoniation of mesitylene, avoiding oxidation of the methyl groups. The resulting nitro compound is reduced to the aniline.

Phenylphosphine is an organophosphorus compound with the chemical formula C6H5PH2. It is the phosphorus analog of aniline. Like other primary phosphines, phenylphosphine has an intense penetrating odor and is highly oxidizable. It is mainly used as a precursor to other organophosphorus compounds. It can function as a ligand in coordination chemistry.

<span class="mw-page-title-main">Michler's ketone</span> Chemical compound

Michler's ketone is an organic compound with the formula of [(CH3)2NC6H4]2CO. This electron-rich derivative of benzophenone is an intermediate in the production of dyes and pigments, for example Methyl violet. It is also used as a photosensitizer. It is named after the German chemist Wilhelm Michler.

<span class="mw-page-title-main">2,4-Diaminotoluene</span> Chemical compound

2,4-Diaminotoluene is an organic compound with the formula C6H3(NH2)2CH3. It is one isomer of six with this formula. It is a white solid, although commercial samples are often yellow-tan.

References

  1. 1 2 3 4 5 NIOSH Pocket Guide to Chemical Hazards. "#0223". National Institute for Occupational Safety and Health (NIOSH).
  2. 1 2 "N,N-Dimethylaniline". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
  3. ↑ Watts, Henry, A Dictionary of Chemistry and the Allied Branches of Other Sciences, Part 2, (London, England: Longmans, Green, and Co., 1881), Methylanilines, p. 1306
  4. ↑ In 1850, August Hofmann announced his synthesis of methylaniline: However, in 1877, the Swiss chemist Alfred Kern (1850–1893) contended that Hofmann's reaction produced only dimethylaniline, not methylaniline: Hofmann found that acetic anhydride reacted only with methylaniline, not with dimethylaniline, and was thus able to show that his reaction produced both the mono- and di-methylated forms of aniline:
  5. ↑ Kahl, Thomas et al. (2007) "Aniline" in Ullmann's Encyclopedia of Industrial Chemistry. John Wiley & Sons: New York. doi : 10.1002/14356007.a02_303
  6. ↑ Jacques, J. and Marquet, A. (1988). "Selective α-Bromination of an Aralkyl Ketone with Phenyltrimethylammonium Tribromide: 2-Bromoacetyl-6-methoxynaphthalene and 2,2-Dibromoacetyl-6-Methoxynaphthalene". Organic Syntheses .{{cite journal}}: CS1 maint: multiple names: authors list (link); Collective Volume, vol. 6, p. 175
  7. ↑ Gessner, Thomas and Mayer, Udo (2002) "Triarylmethane and Diarylmethane Dyes" in Ullmann's Encyclopedia of Industrial Chemistry. Wiley-VCH, Weinheim. doi : 10.1002/14356007.a27_179
  8. ↑ General Info on DMA (N,N-Dimethylaniline), Composites Australia
  9. ↑ Gorrod, J. W.; Gooderham, N. J. (1981). "The in vitro metabolism of N,N-dimethylaniline by guinea pig and rabbit tissue preparations". European Journal of Drug Metabolism and Pharmacokinetics. 6 (3): 195–206. doi:10.1007/BF03189489. PMID   7308239. S2CID   7221074.
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