Diethyl oxalate

Diethyl oxalate
Names
	Other names ethyl oxalate
Identifiers
CAS Number	95-92-1;
3D model (JSmol)	Interactive image;
ChEMBL	ChEMBL3183226;
ChemSpider	6998;
ECHA InfoCard	100.002.241
EC Number	202-464-1;
PubChem CID	7268;
UNII	860M3ZWF6J;
UN number	2525
CompTox Dashboard (EPA)	DTXSID2044472 ;
	InChI InChI=1S/C6H10O4/c1-3-9-5(7)6(8)10-4-2/h3-4H2,1-2H3 Key: WYACBZDAHNBPPB-UHFFFAOYSA-N;
	SMILES CCOC(=O)C(=O)OCC;
Properties
Chemical formula	C6H10O4
Molar mass	146.142 g·mol−1
Appearance	colorless liquid
Density	1.0785 g/cm3
Melting point	−38.5 °C (−37.3 °F; 234.7 K)
Boiling point	186 °C (367 °F; 459 K)
Hazards
	GHS labelling:[1]
Pictograms
Signal word	Warning
Hazard statements	H302, H319
Precautionary statements	P264, P264+P265, P270, P280, P301+P317, P305+P351+P338, P330, P337+P317, P501
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Diethyl oxalate is an organic compound with the formula (CO₂CH₂CH₃)₂. It is the diethyl ester of oxalic acid. Diethyl oxalate is a colorless liquid. It is very similar to dimethyl oxalate but is a liquid at room temperature and has lower solubility in water. Both compounds are reagents in the synthesis of more complex compounds.^[1]

Production

Diethyl oxalate can be obtained by esterification of oxalic acid with ethanol using sulfuric acid as a catalyst. A procedure for the closely related dimethyl oxalate is available:^[2]

2 CH₃CH₂OH + (CO₂H)₂ → (CO₂CH₂CH₃)₂ + 2 H₂O

Reactions

Diethyl oxalate participates in many condensation reactions, usually to produce esters.^[3] ^[4] ^[5]

Diethyl oxalate is often used to prepare heterocycles. It is for example a precursor to 3,4-ethylenedioxythiophene.^[6] With urea, it condenses to give parabanic acid.^[7]

References

^ Garratt, Peter J. (2001). "Diethyl Oxalate". Encyclopedia of Reagents for Organic Synthesis. doi:10.1002/047084289X.rd207. ISBN 0-471-93623-5.
^ Everett Bowden (1930). "Methyl Oxalate". Organic Syntheses. 10: 78. doi:10.15227/orgsyn.010.0078.
^ Don E. Floyd, Sidney E. Miller (1954). "Cetylmalonic Ester". Organic Syntheses. 34: 13. doi:10.15227/orgsyn.034.0013.
^ P. A. Levene, G. M. Meyer (1936). "Ethyl Phenylmalonate". Organic Syntheses. 16: 33. doi:10.15227/orgsyn.016.0033.
^ Lester Friedman, Edward Kosower (1946). "α-Ketoglutaric Acid". Organic Syntheses. 26: 42. doi:10.15227/orgsyn.026.0042.
^ Pei, Qibing; Zuccarello, Guido; Ahlskog, Markus; Inganäs, Olle (1994). "Electrochromic and Highly Stable Poly(3,4-ethylenedioxythiophene) Switches Between Opaque Blue-Black and Transparent Sky Blue". Polymer. 35 (7): 1347–1351. doi:10.1016/0032-3861(94)90332-8.
^ Joseph I. Murray (1957). "Parabanic Acid". Organic Syntheses. 37: 71. doi:10.15227/orgsyn.037.0071.

[1] Garratt, Peter J. (2001). "Diethyl Oxalate". Encyclopedia of Reagents for Organic Synthesis. doi:10.1002/047084289X.rd207. ISBN 0-471-93623-5.

[2] Everett Bowden (1930). "Methyl Oxalate". Organic Syntheses. 10: 78. doi:10.15227/orgsyn.010.0078.

[3] Don E. Floyd, Sidney E. Miller (1954). "Cetylmalonic Ester". Organic Syntheses. 34: 13. doi:10.15227/orgsyn.034.0013.

[4] P. A. Levene, G. M. Meyer (1936). "Ethyl Phenylmalonate". Organic Syntheses. 16: 33. doi:10.15227/orgsyn.016.0033.

[5] Lester Friedman, Edward Kosower (1946). "α-Ketoglutaric Acid". Organic Syntheses. 26: 42. doi:10.15227/orgsyn.026.0042.

[6] Pei, Qibing; Zuccarello, Guido; Ahlskog, Markus; Inganäs, Olle (1994). "Electrochromic and Highly Stable Poly(3,4-ethylenedioxythiophene) Switches Between Opaque Blue-Black and Transparent Sky Blue". Polymer. 35 (7): 1347–1351. doi:10.1016/0032-3861(94)90332-8.

[7] Joseph I. Murray (1957). "Parabanic Acid". Organic Syntheses. 37: 71. doi:10.15227/orgsyn.037.0071.

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