Ethyl diacetyl succinate

One modification of this procedure has. been to react the ethyl diacetyl succinate with diamine on an equimolar basis to give an N(aminophenyl)pyrrole diester which can then undergo further condensation to give the polyimide directly. 

Synthesis of bis(pyrrole) monomers. The condensation of ethyl diacetyl succinate with amines to give dialkyl esters of N substituted pyrroles proceeds in near quantitative yields to the bis(dicarboethoxy dimethyl pyrrole). 

Synthesis of N-(amino aryl) pyrrole dicarboxylate monomer. This type of polyimide precursor was prepared by the method of Knorr, who first described these preparations almost 100 years ago. The preparation proceeds readily by refluxing of ethyl diacetyl succinate with... 

The N-(aminophenyl) pyrrole dlester was prepared by a similar procedure using equal molar quantities of ethyl diacetyl succinate and an aromatic diamine. 

Weems, on electrolyzing the sodium salt of methylmalonic ester in alcoholic solution, obtained dimethyl-etharie-tetracarboxylic ester ethyl-malonic ester yielded diethyl-etkane-tetracarboxylic ester and aceto-acetic ester was changed to diacetyl-succinic ester. 

Among the compounds commonly determined in research laboratories are diacetyl, 2,3-butandiol, glycerol, citramalic acid, amino acids (especially proline), histamine, ammonia, succinic acid, phosphate, ash, alkalinity of the ash, ethyl, acetate, methyl anthranilate, total volatile esters, higher alcohols (both total and individually) phenolic compounds, etc. An elegant method for determining ethyl esters, capronate, caprylate, caprinate, and laurate using carbon disulfide extraction and GLC has been published (123). 

---