''N''-Methylethanolamine is an alkanolamine with the formula CH₃NHCH₂CH₂OH. It is

flammable A combustible material is something that can burn (i.e., ''combust'') in air. A combustible material is flammable if it ignites easily at ambient temperatures. In other words, a combustible material ignites with some effort and a flammable mat ...

, corrosive, colorless,

viscous The viscosity of a fluid is a measure of its resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water. Viscosity quantifies the inter ...

liquid A liquid is a nearly incompressible fluid that conforms to the shape of its container but retains a (nearly) constant volume independent of pressure. As such, it is one of the four fundamental states of matter (the others being solid, gas, a ...

.Matthias Frauenkron, Johann-Peter Melder, Günther Ruider, Roland Rossbacher, Hartmut Höke "Ethanolamines and Propanolamines" in ''Ullmann's Encyclopedia of Industrial Chemistry'', 2002, Wiley-VCH, Weinheim. It is an intermediate in the

biosynthesis Biosynthesis is a multi-step, enzyme-catalyzed process where substrates are converted into more complex products in living organisms. In biosynthesis, simple compounds are modified, converted into other compounds, or joined to form macromolecules. ...

of choline. With both an

amine In chemistry, amines (, ) are compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are formally derivatives of ammonia (), wherein one or more hydrogen atoms have been replaced by a substituen ...

and a

hydroxyl In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula and composed of one oxygen atom covalently bonded to one hydrogen atom. In organic chemistry, alcohols and carboxylic acids contain one or more hydroxy ...

functional group In organic chemistry, a functional group is a substituent or moiety in a molecule that causes the molecule's characteristic chemical reactions. The same functional group will undergo the same or similar chemical reactions regardless of the rest ...

s, it is a useful intermediate in the

chemical synthesis As a topic of chemistry, chemical synthesis (or combination) is the artificial execution of chemical reactions to obtain one or several products. This occurs by physical and chemical manipulations usually involving one or more reactions. In moder ...

of various products including polymers and pharmaceuticals. It is also used as a

solvent A solvent (s) (from the Latin '' solvō'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid. Water is a solvent for ...

, for example in the processing of

natural gas Natural gas (also called fossil gas or simply gas) is a naturally occurring mixture of gaseous hydrocarbons consisting primarily of methane in addition to various smaller amounts of other higher alkanes. Low levels of trace gases like carbo ...

, where it is used together with its analogs

ethanolamine Ethanolamine (2-aminoethanol, monoethanolamine, ETA, or MEA) is an organic chemical compound with the formula or . The molecule is bifunctional, containing both a primary amine and a primary alcohol. Ethanolamine is a colorless, viscous liquid wit ...

and dimethylethanolamine.

Production

''N''-Methylethanolamine is produced industrially by reacting ethylene oxide with excess

methylamine Methylamine is an organic compound with a formula of . 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. Methylamine is sold as a solution in methanol, ...

in aqueous solution. This reaction yields a mixture of the 1:1 addition product NMEA (1) and - by a further addition of another ethylene oxide - the 1:2 addition product methyl diethanolamine (MDEA) (2): Synthesis NMEA MDEA

In order to obtain high yields of the desired target product, the reactants are continuously fed to a flow reactor and reacted with a more than two-fold excess of methylamine. In the downstream process steps, the excess methylamine and the water is removed and NMEA (bp. 160 °C) and MDEA (bp. 243 °C) are isolated from the product mixture by fractional distillation. The poly(methyl-ethanolamine) formed by further addition of ethylene oxide to methylethanolamine remains in the distillation bottoms.

Properties

''N''-Methylethanolamine is a clear, colorless,

hygroscopic Hygroscopy is the phenomenon of attracting and holding water molecules via either absorption or adsorption from the surrounding environment, which is usually at normal or room temperature. If water molecules become suspended among the substance ...

, amine-like smelling liquid which is miscible with water and ethanol in any ratio. Aqueous solutions react strongly basic and are therefore corrosive. The substance is easily biodegradable and has no potential of

bioaccumulation Bioaccumulation is the gradual accumulation of substances, such as pesticides or other chemicals, in an organism. Bioaccumulation occurs when an organism absorbs a substance at a rate faster than that at which the substance is lost or eliminated ...

due to its water miscibility. NMEA is not mutagenic, but in the presence of

nitrite The nitrite polyatomic ion, ion has the chemical formula . Nitrite (mostly sodium nitrite) is widely used throughout chemical and pharmaceutical industries. The nitrite anion is a pervasive intermediate in the nitrogen cycle in nature. The name ...

, carcinogenic

nitrosamine In organic chemistry, nitrosamines (or more formally ''N''-Nitrosamines) are organic compounds with the chemical structure , where R is usually an alkyl group. They feature a nitroso group () bonded to a deprotonated amine. Most nitrosamines are ...

s can be formed from the compound, as it is a secondary amine.

Use

Like other alkylalkanolamines, ''N''-methylethanolamine is used in water- and solvent-based paints and coatings as a solubilizer for other components, such as pigments and as a stabilizer. In cathodic dip-coating, ''N''-methylaminoethanol serves as cation neutralizer for the partial neutralization of the

epoxy resin Epoxy is the family of basic components or cured end products of epoxy resins. Epoxy resins, also known as polyepoxides, are a class of reactive prepolymers and polymers which contain epoxide groups. The epoxide functional group is also coll ...

. It also serves as a chain extender in the reaction of high molecular weight polyepoxides with polyols. Being a base, ''N''-methylaminoethanol forms neutral salts with

fatty acid In chemistry, particularly in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated or unsaturated. Most naturally occurring fatty acids have an unbranched chain of an even number of carbon atoms, fr ...

s, which are used as surfactants (soaps) with good emulsifying properties and find applications in textile and personal care cleansing products. When bleaching cotton-polyester blends, NMEA is used as a brightener.The Dow Chemical Company
''Alkyl Alkanolamines''
, March 2003. By methylation of ''N''-methylaminoethanol,

dimethylaminoethanol Dimethylethanolamine (DMAE or DMEA) is an organic compound with the formula (CH3)2NCH2CH2OH. It is bifunctional, containing both a tertiary amine and primary alcohol functional groups. It is a colorless viscous liquid. It is used in skin care produ ...

and choline 2-hydroxyethyl)-trimethyl-ammonium chloridecan be prepared. In the reaction of ''N''-methylaminoethanol with fatty acids, long-chain ''N''-methyl-''N''-(2-hydroxyethyl)amides are formed upon elimination of water. These are used as neutral surfactants. Such amides also act as flow improvers and

pour point depressant Pour point depressants are used to allow the use of petroleum based mineral oils at lower temperatures. The lowest temperature at which a fuel or oil will pour is called a pour point. Wax crystals, which form at lower temperatures, may interfere wit ...

s in heavy oils and

middle distillate An oil refinery or petroleum refinery is an industrial process plant where petroleum (crude oil) is transformed and refined into useful products such as gasoline (petrol), diesel fuel, asphalt base, fuel oils, heating oil, kerosene, lique ...

s. By catalytic oxidation of ''N''-methylaminoethanol, the

non-proteinogenic amino acid In biochemistry, non-coded or non-proteinogenic amino acids are distinct from the 22 proteinogenic amino acids (21 in eukaryotesplus formylmethionine in eukaryotes with prokaryote organelles like mitochondria) which are naturally encoded in the ge ...

sarcosine is obtained. ''N''-methylaminoethanol plays a role as a building block for the synthesis of crop protection compounds and pharmaceuticals, such as in the first stage of the reaction sequence to the antihistamine and

antidepressant Antidepressants are a class of medication used to treat major depressive disorder, anxiety disorders, chronic pain conditions, and to help manage addictions. Common side-effects of antidepressants include dry mouth, weight gain, dizziness, hea ...

mianserin Mianserin, sold under the brand name Tolvon among others, is an atypical antidepressant that is used primarily in the treatment of depression in Europe and elsewhere in the world. It is a tetracyclic antidepressant (TeCA). Mianserin is closely ...

(Tolvin) and to the non-analgesic

Nefopam Nefopam, sold under the brand name Acupan among others, is a centrally acting, non-opioid painkilling medication, that is primarily used to treat moderate to severe pain. Nefopam acts in the brain and spinal cord to relieve pain via novel mecha ...

(Ajan). In analogy to other aziridines, ''N''-methylaziridine can be obtained by a Wenker synthesis from ''N''-methylaminoethanol. This is done either via the sulfuric acid ester or after replacement of the

hydroxy group In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula and composed of one oxygen atom covalently bonded to one hydrogen atom. In organic chemistry, alcohols and carboxylic acids contain one or more hydroxy ...

by a chlorine atom (for example by thionyl chloride or

chlorosulfuric acid Chlorosulfuric acid (IUPAC name: sulfurochloridic acid) is the inorganic compound with the formula HSO3Cl. It is also known as chlorosulfonic acid, being the sulfonic acid of chlorine. It is a distillable, colorless liquid which is hygroscopic and ...

J.H. Drese
''The design, synthesis, and characterization of aminosilica adsorbants for CO₂ capture from dilute sources''
(PDF; 5,3 MB), Ph.D. Thesis, Georgia Institute of Technology, Dezember 2010, S. 175.) to ''N''-methyl-2-chloroethylamine and then by using a strong base (cleavage of HCl) in an intramolecular nucleophilic substitution: Synthesis Aziridin

It reacts with carbon disulfide to give ''N''-methyl-2-thiazolidinethione.

References

{{DEFAULTSORT:Methylethanolamine, N- Primary alcohols Amines

Production

Properties

Use

See also

References