1897-98.] On Ethyl Potassium Diethoxy succinate. 
255 
On the Electrolysis of Ethyl Potassium Diethoxy- 
succinate. By Prof. Crum Brown and Dr H. W. 
Bolam. 
(Read July 18, 1898.) 
The method of electrolytic synthesis of dibasic acids described 
by Cram Brown and Walker has hitherto been found to be 
applicable to dibasic acids of the formula C n H 2n (COOH) 2 , whether 
normal or with side chains, and to camphoric acid, -which is no 
doubt a saturated cyclic compound. In all other cases which 
have been tried the anion is oxidised and broken up. 
One of us long ago found that this was the case with tartaric 
acid, and in 1894 v. Miller and Hofer showed that when the salts 
of monobasic hydroxy-acids are electrolysed the anion is oxidised 
and broken up. They showed that this is the case also with 
methoxyacetic acid, so that it would appear that the replacement 
of H by OR', where R' is an alkyl, leads to the same destruction 
of the anion as does the replacement of H by OIT. We examined 
ethoxy succinic acid, and found that here also no ethereal layer is 
formed on the electrolysis of the ethyl potassium salt. 
Very different was the case with diethoxysuccinic acid. 
Professor Purdie has shown that it is possible to add the elements 
of alcohol to fumaric and maleic ethers by means of sodium and 
anhydrous alcohol {Trans. Chem. Soc., 1885, vol. 47, 856, and 
1891, vol. 59, 468). He gave us permission to apply this method 
to acetylendicarboxylic ether, where, by the addition of two 
molecules of alcohol, diethoxysuccinic ether should be formed. 
Acetylendicarboxylic acid was prepared according to Baeyer’s 
directions by the action of alcoholic potash on dibromsuccinic 
acid. On treating this acid with alcohol and sulphuric acid the 
acetylendicarboxylic ester was obtained in small quantity, the yield 
being from 25 to 30%. 
The acetylendicarboxylic ester was then mixed with twice its 
weight of alcohol, and then a small quantity of sodium ethylate 
dissolved in alcohol was added. The solution usually remained 
alkaline for 36 hours, and then a further small quantity of sodium 
was added. After allowing to stand at the ordinary laboratory 
