Electrosynthesis of arylalkanoic acids by oxidation of the corresponding arylalkanols at the Ni anode in aqueous alkali

Abstract

The electrochemical synthesis of a series of aryl(aryloxy)alkanoic acids was carried out by the electrocatalytic oxidation of the corresponding alcohols with the general formula RCH2CH2OH (R = Ar, CH2Ph, OPh) in an undivided cell at the NiOOH electrode in aqueous alkali. The efficiency of the process depends on the structure of the starting alcohols, particularly, on the donor-acceptor properties of the substituent R. These properties determine the possibility of the primarily formed RCH2COO− anion to be oxidized forming by-products. The yield of the target acids upon the oxidation of 2-(2-hydroxyethyl)pyridine, 2-phenylethanol, 3-phenylpronan-1-ol, and 2-phenoxyethanol was 15, 53, 75, and 93%, respectively, based on the reacted alcohol.