Ethyl Oxalacetate
Structural Formula Vector Image
Title: Ethyl Oxalacetate
CAS Registry Number: 108-56-5
CAS Name: Oxobutanedioic acid diethyl ester
Additional Names: diethyl oxalacetate; oxaloacetic ester
Molecular Formula: C8H12O5
Molecular Weight: 188.18
Percent Composition: C 51.06%, H 6.43%, O 42.51%
Line Formula: C2H5OOCCH2COCOOC2H5
Literature References: Obtained by the action of sodium on a mixture of ethyl oxalate and ethyl acetate.
Properties: Oily liquid. d420 1.131. bp24 132°. nD16.6 1.45614. Insol in water. Miscible with alc, benzene, ether. Dec when boiled at ordinary pressure. With water it gradually dec into alc and acetic and oxalic acids.
Boiling point: bp24 132°
Index of refraction: nD16.6 1.45614
Density: d420 1.131
 
Derivative Type: Semicarbazone
Properties: Crystals, mp 162°.
Melting point: mp 162°

The sodium salt of diethyl oxalacetate is a stable material which finds utility in the synthesis of pyrazolone derivatives, as an intermediate in the preparation of dyes and medicinal products, and more recently in the preparation of herbicides. Salts of this type and their preparation are disclosed in U.S. Pat. No. 1,948,201 in which metallic sodium is dissolved in ethanol to form sodium ethylate, after which the solution is cooled to 0° C.-15° C. and stoichiometric amounts of diethyl oxalate and ethyl acetate are added thereto. The reaction is allowed to proceed for a period of 2-4 hours at 0° to 15° C. and the reaction mixture is then boiled for 15 to 30 minutes, cooled, and thereafter filtered to recover a cake of sodium ethyl oxalacetate. 

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US patent US4902819A  Hoechst Celanese Corp  1988-09-22

What is claimed is:
1. In a method of preparing sodium diethyl oxalacetate by reaction of sodium ethoxide, diethyl oxalate and ethyl acetate, the improvement which comprises adding sodium ethoxide to a mixture of diethyl oxalate and ethyl acetate while maintaining a temperature of about 0° C. to 40° C., reacting said ethoxide, oxalate and acetate mixture for a period of time sufficient to obtain a product mixture containing sodium diethyl oxalacetate, heating the product mixture to a temperature of 70° C. to 80° C. for a period of time ranging from 1/4 to 2 hours, cooling the product mixture to room temperature, and thereafter recovering sodium diethyloxalacetate.
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