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Diglyme, or bis(2-methoxyethyl) ether, is a solvent with a high boiling point. It is an organic compound which is the dimethyl ether of diethylene glycol. (The name "diglyme" is a portmanteau of "diglycol methyl ether.") It is a clear, colorless liquid with a slight ether-like odor. It is miscible with water, alcohols, diethyl ether, and hydrocarbon solvents. It is prepared by a reaction of dimethyl ether and ethylene oxide over an acid catalyst.[2]

Skeletal formula of diglyme
Space-filling model of the diglyme molecule
Preferred IUPAC name
Other names
2-Methoxyethyl ether
Di(2-methoxyethyl) ether
Diethylene glycol dimethyl ether
3D model (JSmol)
ECHA InfoCard 100.003.568
EC Number 203-924-4
Molar mass 134.18 g·mol−1
Density 0.937 g/mL
Melting point −64 °C (−83 °F; 209 K)
Boiling point 162 °C (324 °F; 435 K)
Toxic (T)
Flammable (F)
R-phrases (outdated) R60 R61 R10 R19
S-phrases (outdated) S53 S45
Flash point 57 °C (135 °F; 330 K)
Related compounds
Related compounds
Diethylene glycol diethyl ether, ethylene glycol dimethyl ether
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references


Its stability, even at high pH values, makes it an excellent solvent for reactions with strong bases or reactions that require high temperatures.

Diglyme is mainly used as a solvent. It serves as a chelate for alkali metal cations, leaving anions more active. Therefore, reactions involving organometallic reagents, such as Grignard reactions or metal hydride reductions, may have significantly enhanced reaction rates.[3] Diglyme is also used as a solvent in hydroboration reactions with diborane.


  1. ^ Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. p. 704. doi:10.1039/9781849733069-FP001. ISBN 978-0-85404-182-4.
  2. ^ Siegfried Rebsdat; Dieter Mayer, "Ethylene Glycol", Ullmann's Encyclopedia of Industrial Chemistry, Weinheim: Wiley-VCH, doi:10.1002/14356007.a10_101
  3. ^ J. E. Ellis, A. Davison (1976). "Tris[Bis(2-Methoxyethyl)Ether]Potassium and Tetraphenylarsonium Hexacarbonylmetallates(1–) of Niobium and Tantalum". Inorg. Synth. 16: 68–73. doi:10.1002/9780470132470.ch21.