Editing Dimethylaniline

{{About|N,N-dimethylaniline|other constitutional isomers|xylidine}}
{{chembox
| Watchedfields = changed
| verifiedrevid = 460790058
| Name = ''N'',''N''-Dimethylaniline
| ImageFileL1 = Dimethylaniline skeletal.svg
| ImageSizeL1 = 85px
| ImageAltL1 = Skeletal formula of dimethylaniline
| ImageFileR1 = Dimethylaniline-3D-balls-2.png
| ImageSizeR1 = 125
| ImageAltR1 = Ball-and-stick model of the dimethylaniline molecule
| PIN = ''N'',''N''-Dimethylaniline
| OtherNames = DMA<br />Dimethylaminobenzene<br />''N'',''N''-Dimethylbenzeneamine<br />''N'',''N''-Dimethylphenylamine
|Section1={{Chembox Identifiers
| ChEMBL_Ref = {{ebicite|correct|EBI}}
| ChEMBL = 371654
| PubChem = 949
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 924
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C8H11N/c1-9(2)8-6-4-3-5-7-8/h3-7H,1-2H3
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = JLTDJTHDQAWBAV-UHFFFAOYSA-N 
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo = 121-69-7
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 7426719369
| KEGG_Ref = {{keggcite|correct|kegg}}
| KEGG = C02846
| ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEBI = 16269
| SMILES = CN(C)c1ccccc1}}
|Section2={{Chembox Properties
| C=8 | H=11 | N=1
| Appearance = Colorless liquid
| Odor = amine-like
| Density = 0.956 g/mL
| MeltingPtC = 2
| BoilingPtC = 194
| Solubility = 2% (20°C)<ref name=PGCH/>
| VaporPressure = 1 mmHg (20°C)<ref name=PGCH/>
| MagSus = −89.66·10<sup>−6</sup> cm<sup>3</sup>/mol
}}
|Section3={{Chembox Hazards
| MainHazards =
| FlashPtC = 63
| ExternalSDS = [http://hazard.com/msds/mf/baker/baker/files/d6040.htm External MSDS]
| AutoignitionPtC =
| PEL = TWA 5 ppm (25 mg/m<sup>3</sup>) [skin]<ref name=PGCH>{{PGCH|0223}}</ref>
| IDLH = 100 ppm<ref name=PGCH/>
| REL = TWA 5 ppm (25 mg/m<sup>3</sup>) ST 10 ppm (50 mg/m<sup>3</sup>) [skin]<ref name=PGCH/> 
| LD50 = 1410 mg/kg (rat, oral)<ref name=IDLH>{{IDLH|121697|N,N-Dimethylaniline}}</ref>
| LCLo = 50 ppm (rat, 4 hr)<ref name=IDLH/>
 }}
}}

'''''N'',''N''-Dimethylaniline''' ('''DMA''') is an [[organic compound|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]].

==Preparation==
DMA was first reported in 1850 by the German chemist [[August Wilhelm von Hofmann|A. W. Hofmann]], who prepared it by heating aniline and [[iodomethane]]:<ref>Watts, Henry, ''A Dictionary of Chemistry and the Allied Branches of Other Sciences'', Part 2, (London, England:  Longmans, Green, and Co., 1881), Methylanilines, [https://books.google.com/books?id=NfMfAQAAMAAJ&pg=PA1306 p. 1306]</ref><ref>In 1850, August Hofmann announced his synthesis of methylaniline:
*  Hofmann, A. W. (1850) [http://rstl.royalsocietypublishing.org/content/140/93.full.pdf+html "Researches regarding the molecular constitution of the volatile organic bases,"] ''Philosophical Transactions of the Royal Society of London'', '''140''' :  93–131 ;  see especially pp. 113-114.
However, in 1877, the Swiss chemist Alfred Kern (1850–1893) contended that Hofmann's reaction produced only dimethylaniline, not methylaniline:
*  Kern, A. (1877) [https://babel.hathitrust.org/cgi/pt?id=hvd.cl1hz2;view=1up;seq=205 "Ueber die Darstellung von Monomethylanilin"] (On the preparation of monomethylaniline), ''Berichte der deutschen chemischen Gesellschaft'', '''10''' :  195–199.
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:
*  Hofmann, A. W. (1877) [https://babel.hathitrust.org/cgi/pt?id=hvd.cl1hz2;view=1up;seq=613 "Versuche über die Einwirkung des Chlor-, Brom- und Jodmethyls auf Anilin"] (Experiments on the reaction of methyl chloride, bromide and iodide with aniline), ''Berichte der deutschen chemischen Gesellschaft'', '''10''' :  591–601.</ref>
:C<sub>6</sub>H<sub>5</sub>NH<sub>2</sub>  +  2 CH<sub>3</sub>I   →   C<sub>6</sub>H<sub>5</sub>N(CH<sub>3</sub>)<sub>2</sub> + 2 [[hydrogen iodide|HI]] <!-- probably the aniline serves as base also-->
DMA is produced industrially by [[alkylation]] of [[aniline]] with [[methanol]] in the presence of an acid catalyst:<ref name=Ullmann>Kahl, Thomas ''et al.'' (2007) "Aniline" in ''Ullmann's Encyclopedia of Industrial Chemistry''. John Wiley & Sons: New York. {{doi|10.1002/14356007.a02_303}}</ref>
:C<sub>6</sub>H<sub>5</sub>NH<sub>2</sub>  +  2 [[methanol|CH<sub>3</sub>OH]]  →  C<sub>6</sub>H<sub>5</sub>N(CH<sub>3</sub>)<sub>2</sub>  +  2 H<sub>2</sub>O
Similarly, it is also prepared using [[dimethyl ether]] as the methylating agent.
==Reactions==
Dimethylaniline undergoes many of the reactions expected for an aniline, being weakly basic and reactive toward electrophiles.<ref>{{cite journal |doi=10.15227/orgsyn.019.0079 |title=P-Thiocyanatodimethylaniline |journal=Organic Syntheses |date=1939 |volume=19 |page=79|first1=R. Q. |last1=Brewster|first2=Wesley|last2=Schroeder }}</ref> 

It is [[nitration|nitrated]] to produce [[tetryl]], a derivative with four [[nitro compound|nitro]] groups which was once used as explosive.  In acidic solution, the initial nitration gives 3-nitrodimethylaniline.<ref>{{cite journal |doi=10.15227/orgsyn.027.0062 |title=m-Nitrodimethylaniline |journal=Organic Syntheses |date=1947 |volume=27 |page=62|author=Howard M. Fitch }}.</ref>  It reacts with [[n-Butyllithium|butyllithium]] to give the 2-lithio derivative. Electrophilic methylating agents like [[dimethyl sulfate]] attack the amine to give the quaternary ammonium salt:<ref>{{OrgSynth | | author = Jacques, J. and Marquet, A. | title = Selective α-Bromination of an Aralkyl Ketone with Phenyltrimethylammonium Tribromide: 2-Bromoacetyl-6-methoxynaphthalene and 2,2-Dibromoacetyl-6-Methoxynaphthalene | volume = 53 | pages = 111 | year = 1973 | doi =  10.15227/orgsyn.053.0111}}</ref>
:C<sub>6</sub>H<sub>5</sub>N(CH<sub>3</sub>)<sub>2</sub>  +(CH<sub>3</sub>O)<sub>2</sub>SO<sub>2</sub>  →  C<sub>6</sub>H<sub>5</sub>N(CH<sub>3</sub>)<sub>3</sub>CH<sub>3</sub>OSO<sub>3</sub>

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

==Applications==
DMA is a key precursor to commercially important [[triarylmethane dye]]s such as [[malachite green]] and [[crystal violet]].<ref>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}}</ref>  DMA serves as a promoter in the curing of polyester and vinyl ester resins.<ref>[https://www.compositesaustralia.com.au/for-industry/health-and-safety/dma/ General Info on DMA (N,N-Dimethylaniline)], Composites Australia</ref>  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.<ref>{{Cite journal | doi = 10.1007/BF03189489|pmid=7308239| title = The in vitro metabolism of N,N-dimethylaniline by guinea pig and rabbit tissue preparations| journal = European Journal of Drug Metabolism and Pharmacokinetics| volume = 6| issue = 3| pages = 195–206| year = 1981| last1 = Gorrod | first1 = J. W.| last2 = Gooderham | first2 = N. J.|s2cid=7221074}}</ref>

==References==
{{reflist}}

[[Category:Anilines]]
[[Category:Dimethylamino compounds]]
[[Category:tertiary amines]]