Dimethoxyethane

Not to be confused with dimethoxymethane.

Dimethoxyethane
Names


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
3D model (Jmol)	Interactive image
ChEBI	CHEBI:42263^N
ChemSpider	13854808^Y
ECHA InfoCard	100.003.451
RTECS number	KI1451000
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
SMILES COCCOC
Properties
Chemical 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 (DSD)	Flammable (F) Toxic (T) Repr. Cat. 2
R-phrases	R60, R61, R11, R19, R20
S-phrases	S53, S45
NFPA 704	2 2 0
Flash point	−2 °C (28 °F; 271 K)
Related compounds
Related Ethers	Dimethoxymethane
Related compounds	Ethylene glycol 1,4-Dioxane Diethylene glycol dimethyl ether
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is ^YN ?)
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, especially in batteries.^[1] Dimethoxyethane is miscible with water.

Production

Monoglyme may be manufactured by a number of methods:^[2]

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

Applications as solvent and ligand

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

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.

References

↑ D. Berndt, D. Spahrbier, "Batteries" in Ullmann’s Encyclopedia of Industrial Chemistry 2005, Wiley-VCH, Weinheim. doi:10.1002/14356007.a03_343
↑ Dimethoxyethane

External links

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