N-Methylethanolamine
- Monomethyl ethanolamine
- 2- methylaminoethanol
- 2- methylaminoethanol
- (2- hydroxyethyl)- methyl-amine
- NMEA
- NMEOA
Colorless to pale yellow liquid with an amine-like odor
Liquid
0.94 g • cm -3 ( 20 ° C)
-5 ° C
160 ° C.
1 hPa (20 ° C)
Miscible with water, ethanol,
1.4390 (20 ° C)
Risk
Template: Infobox chemical / molecular formula search available
N- methyl ethanolamine ( NMEA, also 2- methylaminoethanol ) is both a monovalent primary alcohol and a secondary amine and represents a bifunctional synthetic building block for a variety of secondary products dar. NMEA is a colorless liquid that smells similar to amine and reacts as a base in water.
Production
N- methyl ethanolamine is produced industrially in aqueous solution by reacting ethylene oxide with excess methylamine. The result is a mixture of the 1:1 addition product NMEA (1) and - by further addition of an EO unit - the 1:2 addition product methyldiethanolamine ( MDEA) (2):
To achieve high yields in the desired target product NMEA the reactants are continuously fed with a more than two -fold excess of methylamine accurate maintenance of pressure and temperature of a flow reactor and the reaction gebracht.In downstream processing steps, the excess methylamine and the water is removed and the product mixture by fractional distillation into NMEA (bp 160 ° C) and MDEA (bp 243 ° C) separated. The products resulting from further addition of ethylene oxide to the methyl ethanolamine formed poly [ methyl- ethanolamine ] remain in the distillation bottom.
Properties
N- methyl ethanolamine is a clear, colorless, hygroscopic, amine-like smelling liquid that is miscible in all proportions with water and ethanol and strong bases in aqueous solution reacts ( pH 13.6 at 100 g · l-1 (20 ° C ) ) and therefore corrosive and corrosive effect. The substance is readily biodegradable and has no bioaccumulation due to their miscibility with water. NMEA is not mutagenic in the presence of nitrite but can be formed from NMEA as the secondary amine carcinogenic nitrosamines. Water hazard class 1 - low hazard to waters.
Use
N-methyl ethanolamine as other alkylalkanolamines in water and solvent-based paints and coatings, as solubilizers for other components, such as pigments and used as a stabilizer.
In the cathodic dip painting NMEA serves as in the partial neutralization of cationic dispersing agent for the epoxy resin and as a chain in the reaction of high molecular weight polyepoxide with polyols.
NMEA forms as the base with fatty acids neutral salts, which are surface-active soaps with good emulsifying properties and find applications in textile and personal care cleansing products. In the bleaching of cotton - polyester blends NMEA is used as a brightener.
By methylation of N- methylaminoethanol and dimethylaminoethanol choline [(2 -hydroxyethyl) trimethyl ammonium chloride ] accessible.
In the reaction of fatty acids with NMEA caused dehydration long chain N-methyl- N-(2 -hydroxyethyl) amide, which are used as neutral surfactants. Such amides act as flow improvers and pour point depressants (English pour point depressant ) in heavy oils and middle distillates.
By catalytic oxidation of the non- proteinogenic amino acid NMEA sarcosine is obtained.
N- methylaminoethanol plays as a building block for the synthesis of pesticides and drugs play a role, such as in the first stage of the reaction sequence for antihistamine and antidepressant mianserin ( Tolvin ®) and non- opioids analgesic nefopam ( Ajan ®).
In analogy to aziridine, N- methylaziridine by Wenker synthesis from NMEA over the sulfuric acid ester or by replacement of the hydroxy group by a chlorine atom,
For example by means of thionyl chloride or chlorosulfonic acid to give the N -methyl-2 - chloroethylamine using a strong base ( elimination of HCl ) can be obtained by an intramolecular nucleophilic substitution.
Related compounds
- Monoethanolamine
- Dimethylaminoethanol
- Choline