Dimethoxyethane
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Dimethoxyethane".

Dimethoxyethane
IUPAC name	1,2-Dimethoxyethane
Other names	DME, glyme, monoglyme, dimethyl glycol, ethylene glycol dimethyl ether, dimethyl cellosolve
Identifiers
CAS number	[110-71-4]
RTECS number	KI1451000
SMILES	COCCOC
Properties
Molecular formula	C4H10O2
Molar mass	90.12 g/mol
Appearance	colorless liquid
Density	0.8683 g/cm3, liquid
Melting point	-58 °C
Boiling point	85 °C
Solubility in water	miscible
Hazards
EU classification	Flammable (F) Toxic (T) Repr. Cat. 2
R-phrases	R60, R61, R11, R19, R20
S-phrases	S53, S45
Flash point	−2 °C
Related compounds
Related Ethers	Dimethoxymethane
Related compounds	Ethylene glycol 1,4-Dioxane
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references

Dimethoxyethane, also known as glyme, monoglyme, dimethyl glycol, ethylene glycol dimethyl ether, dimethyl cellosolve, and DME, is a clear, colorless, aprotic, and liquid ether that is used as a solvent. Dimethoxyethane is highly soluble in water.

Dimethoxyethane is often used as a higher boiling alternative to diethyl ether and THF. Dimethoxyethane forms chelate complexes with cations and acts as a bidentate ligand. It is therefore often used in organometallic chemistry like Grignard reactions, hydride reductions, and palladium catalyzed reactions like Suzuki reactions and Stille coupling. Dimethoxyethane is also a good solvent for oligo- and polysaccharides.

The lowest energy form of dimethoxyethane in the gas phase is the gauche, rather than the anti conformer

Production

Monoglyme be manufactured by a number of methods:^[1]

• via the Williamson ether synthesis — reacting the sodium salt of 2-methoxyethanol (previously prepared by reaction with sodium) with chloromethane:

2 CH₃OCH₂CH₂OH + 2 Na → 2 CH₃OCH₂CH₂ONa + H₂↑

CH₃OCH₂CH₂ONa + CH₃Cl → CH₃OCH₂CH₂OCH₃ + NaCl

• via the alkylation of 2-methoxyethanol with dimethyl sulfate
• by the cleavage of ethylene oxide in presence of dimethyl ether. This reaction is catalyzed by Lewis acids (e.g. boron trifluoride or its complex with dimethyl ether). This route is not particularly selective and produces di- tri, tetra- and other glymes as a by-products. The reaction mixture is separated by distillation:

CH₃OCH₃ + CH₂CH₂O → CH₃OCH₂CH₂OCH₃

Uses

Together with a high-permittivity chemical (eg. propylene carbonate), dimethoxyethane is used as the low-viscosity component of the solvent for electrolytes of lithium batteries.

References

1. ^ Dimethoxyethane

External links

• Clariant Glymes Homepage www.glymes.com
• 1,2-Dimethoxyethane - chemical product info: properties, production, applications.
• International Chemical Safety Card 1568
• Chemical hazard links