It is a most important synthetic reagent; with sodium or sodium ethylate it forms sodio-malonic ester, which reacts readily with alkyl halides, forming alkyl malonic esters, which are again capable of forming sodium derivatives, that by further treatment with alkyl halides yield the di-alkyl malonic esters.
It crystallizes in prisms which melt at 121° C. It yields addition compounds with aniline and naphthalene, and combines directly with potassium methylate, sodio-malonic ester and hydrocyanic ester.
Ethylidene succinic acid or isosuccinic acid, CH3 CH(C02H)2, is produced by the hydrolysis of a-cyanpropionic acid and by the action of methyl iodide on sodio-malonic ester.
CH2 CHz?CU; CO CH 3 CO CH2 from sodio-malonic ester and 0-unsaturated ketones or ketonic esters: /CH, CO (R02C)2CH2+ Ph CH :CH /CH:>; CH(C02R) C07 from aceto-acetic ester and esters of a$-unsaturated acids, followed by elimination of the carboxyl group: CH2 CR', CH 3 CO CH 2.
Acids may be prepared by the action of dihalogen paraffins on sodio-malonic ester, or sodio-aceto-acetic ester (W.
The esters of the acids may also be obtained by condensing sodio-malonic ester with a-halogen derivatives of unsaturated acids: CH H?
The '1.1' dicarboxylic acid is prepared from ethylene dibromide and sodio-malonic ester.
The cis 1.2-cyclo-propane dicarboxylic acid is formed by eliminating carbon dioxide from cyclo-propane tricarboxylic acid -1.2.3 (from 43-dibrompropionic ester and sodio-malonic ester).
When sodio-malonic ester is condensed with trimethylene bromide the chief product is ethyl pentane tetracarboxylate, tetramethylene dicarboxylic ester being also formed, and from this the free acid may be obtained on hydrolysis.
It may be prepared synthetically by fusing its dicarboxylic ester (from malonic ester and sodio malonic ester at 145° C.) with potash (C. W.