Ethyl oxalylsuccinate

The salt is dissolved in 270 ml. of water, and 100 ml. of concentrated hydrochloric acid is added. The ethyl oxalylsuccinate separates as an oil and rises to the surface. It is removed by extracting the mixture with 100-ml. portions of ether until the aqueous solution is almost colorless. The extracts are dried over sodium sulfate, and the ether is distilled under reduced pressure. The ethyl oxalylsuccinate remains in the flask as a yellow oil. The yield is 225-227 g. (82-83%) (Note 4). 

Ethyl oxalylsuccinate has been prepared by the condensation of ethyl oxalate with ethyl succinate in the presence of sodium ethoxide or of potassium ethoxide. The method described above is somewhat more convenient, and has given a higher yield of a better product, than one based upon sodium ethoxide, submitted by A. E. Martell and R. M. Herbst. 

Ethyl orthoformate, 25, 93 28, 60, 84 Ethyl oxalate, 26, 42 Ethyl oxalylsuccinate, 26, 42 Ethyl oxomalonate, 25, 33 Ethyl pentane-1,1,5,5-tetracarbox-YLATE, 23, 18... 

Triethyl oxalylsuccinate, conversion to a-ketoglutaric acid, 44, 67-68 Triethyl phosphite for ethylation of hexachlorocydopentadiene, 43, 90... 

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