Dimethylaniline

This article is about N,N-dimethylaniline. For other constitutional isomers, see xylidine.

N,N-Dimethylaniline

Names
IUPAC name N,N-Dimethylaniline
Other names DMA; Dimethylaminobenzene; N,N-Dimethylbenzeneamine; N,N-Dimethylphenylamine
Identifiers
CAS Number	121-69-7 Y
ChEBI	CHEBI:16269 Y
ChEMBL	ChEMBL371654 Y
ChemSpider	924 Y
Jmol 3D model	Interactive image
KEGG	C02846 Y
PubChem	949
InChI InChI=1S/C8H11N/c1-9(2)8-6-4-3-5-7-8/h3-7H,1-2H3 Y Key: JLTDJTHDQAWBAV-UHFFFAOYSA-N Y
SMILES CN(C)c1ccccc1
Properties
Chemical formula	C8H11N
Molar mass	121.18 g·mol−1
Appearance	Colorless 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)
Solubility in water	2% (20°C)
Vapor pressure	1 mmHg (20°C)
Vapor pressure	{{{value}}}
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Y verify (what is YN ?)
Infobox references

N,N-Dimethylaniline (DMA) is an organic chemical compound, a substituted derivative of aniline. It consists of a tertiary amine, featuring 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 and reactions

DMA was first reported in 1850 by A. W. Hofmann, who prepared it by heating aniline and iodomethane:

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:

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:

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

Applications

DMA is a key precursor to commercially important triarylmethane dyes such as malachite green and crystal violet. DMA serves as a promoter in the curing of polyester and vinyl ester resins. 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. Its derivative 2,4-dimethylaniline is a recalcitrant degradant of the pesticide amitraz and is also an industrial pollutant which is genotoxic, teratogenic and carcinogenic.