Abstract: A process for the preparation of ?-substituted carboxylic acids from the series including ?-hydroxycarboxylic acids and N-substituted-?-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.

Abstract: A process for the preparation of ?-substituted carboxylic acids from the series including ?-hydroxycarboxylic acids and N-substituted-?-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.

Abstract: A process for the electrolytic removal of contaminants from gases, wherein a gas and a liquid electrolyte are passed co- or counter-currently through a fixed bed electrode of an electrolysis cell which has a counterelectrode separated from the fixed bed electrode by a separator and the contaminant is electrochemically converted at an effective cell voltage. Such cells have hitherto been operated in a flooded state. The degree of purification may be substantially increased if the fixed bed electrode is operated as a trickle bed reactor.