Electrosynthesis of 2-hydroxy-2-(4-methoxy-phenyl)-propionic acid methyl ester via electrochemical fixation of carbon dioxide

In the one compartment electrochemical cell equipped with magnesium as the sacrificial anode, stainless steel, titanium(Ti), copper(Cu), nickel(Ni), silver(Ag) as the cathode and in the DMF solution saturated with carbon dioxide, the aimed product 2-hydroxy-2-(4-methoxy-phenyl)-propionic acid methyl ester was electrosynthesized via electrochemical fixation of carbon dioxide. Under the various controlled current conditions, the electrocarboxylation of p-methoxylacetophenone was also measured as a function of supporting electrolytes, cathode materials, the current density, passed charge and temperatures. During the systematic investigation, the maximal yield of 63% was achieved when the electrolysis was carried out under a controlled current density of 5.0 mA/cm² until theoretical charge passed through the cell. Furthermore, the electrochemical behavior of p-methoxylacetophenone has been studied in a three-electrode system, a glassy carbon as the working electrode(d=2 mm), a platinum(Pt) spiral as the counter electrode and Ag/AgI/0.1 mol/L TBAI in DMF as the reference electrode. From analysis of cyclic voltammograms of p-methoxylacetophenone before and after addition of carbon dioxide, a possible electrocarboxylation mechanism was put forward accordingly.