Process for the preparation of alpha-substituted carboxylic acids from the series comprising alpha-hydroxycarboxylic acids and n-substituted-alpha-aminocarboxylic acids

摘要

A process for the preparation of alpha-substituted carboxylic acids from the series including alpha-hydroxycarboxylic acids and N-substituted-alpha-aminocarboxylic acids by cathodic carboxylation with carbon dioxide of a compound corresponding to the general formula R¹-C(-X)R² which is constituted by aldehydes, ketones or N-substituted imines. In the past, that carboxylation has taken place in an undivided electrolytic cell with the use of a sacrificial anode. As described herein, the carboxylation takes place in the absence of a sacrificial anode in an electrolytic cell divided by a separator, at a diamond film cathode. The anode is formed of a material which is stable under electrolytic conditions; in particular, it is a diamond film electrode. The catholyte includes an organic solvent and a conducting salt.