Preparing alpha-substituted carboxylic acids, comprises cathodic carboxylation of a compound in a conducting salt and an organic solvent containing catholyte with carbon dioxide at a diamond cathode layer

摘要

Preparing alpha -substituted carboxylic acid (A), preferably alpha -hydroxycarboxylic acid or N-substituted alpha -amino carboxylic acid, comprises cathodic carboxylation of a compound (I) in a conducting salt and an organic solvent containing catholyte with carbon dioxide at a diamond cathode layer, where the carboxylation takes place in a cathode chamber and an anode chamber separated electrolysis cell, and hydrogen present in the anolyte of anode is converted into hydrogen ions. Preparing alpha -substituted carboxylic acid (A), preferably alpha -hydroxycarboxylic acid or N-substituted alpha -amino carboxylic acid, comprises cathodic carboxylation of a compound of formula (R1-C(=X)R2) (I) in a conducting salt and an organic solvent containing catholyte with carbon dioxide at a diamond cathode layer, where the carboxylation takes place in a cathode chamber and an anode chamber separated electrolysis cell, and hydrogen present in the anolyte of anode is converted into hydrogen ions. R1 : optionally substituted linear, branched or cyclic alkyl, arylalkyl, aryl or heteroaryl; R2 : H or optionally substituted linear, branched or cyclic alkyl, arylalkyl, aryl or heteroaryl; X : O or NR3; and R3 : OH or optionally substituted linear, branched or cyclic alkyl, arylalkyl, aryl or heteroaryl. An independent claim is included for an electrolytic cell with an element, which separates cathode and anode chamber, comprising a permeable anode, a cation as a separator element and a substance-permeable cathode, which are coplanarly arranged, where the anode and cathode directly rest on the separating element.