Dimethoxyethane

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Not to be confused with dimethoxymethane.

Dimethoxyethane

IUPAC name 1,2-Dimethoxyethane
Other names DME, glyme, Ethylene glycol dimethyl ether, monoglyme, dimethyl glycol, dimethyl cellosolve
Identifiers
CAS number	110-71-4^Y
ChemSpider	13854808^Y
RTECS number	KI1451000
Jmol-3D images	Image 1
SMILES COCCOC
InChI InChI=1S/C4H10O2/c1-4(5-2)6-3/h4H,1-3H3^Y Key: SPEUIVXLLWOEMJ-UHFFFAOYSA-N^Y InChI=1/C4H10O2/c1-4(5-2)6-3/h4H,1-3H3 Key: SPEUIVXLLWOEMJ-UHFFFAOYAV
Properties
Molecular formula	C₄H₁₀O₂
Molar mass	90.12 g mol⁻¹
Appearance	Colorless liquid
Density	0.8683 g/cm³
Melting point	−58 °C; −72 °F; 215 K
Boiling point	85 °C; 185 °F; 358 K
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
NFPA 704	3 2 2
Flash point	−2 °C; 28 °F; 271 K
Related compounds
Related Ethers	Dimethoxymethane
Related compounds	Ethylene glycol 1,4-Dioxane Diethylene glycol dimethyl ether
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox 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 miscible with 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 couplings. 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 may 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 diglyme, triglyme, tetraglyme, and other glymes as a by-products. The reaction mixture is separated by distillation:

CH₃OCH₃ + CH₂CH₂O → CH₃OCH₂CH₂OCH₃

Uses

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

References

↑ Dimethoxyethane

External links

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