Green oxidation of aromatic aldehydes to related acids using hydrogen peroxide in acetonitrile under arc discharge


Ali Reza Molla Ebrahimlo
Department of Chemistry, Islamic Azad University, Khoy Branch, Khoy, Iran


Arc discharge catalyzes the oxidation of aromatic aldehydes to the corresponding acids efficiently in the presence of H2O2 as an oxidant. Aqueous hydrogen peroxide oxidizes aldehydes to carboxylic acids by the Arc Discharge Method (ADM) without use of heavy metals. Therefore, this procedure use environmentally for the oxidation of aldehydes. This method possesses functional-group compatibility, easy workup procedure, and shorter reaction time. The reaction is highly dependent on the solvent used. Performance of acetonitrile as solvent in the oxidation of aldehydes was also investigated.


Attention to green chemistry is important for human health and nature; nevertheless, many scientists use toxic and harmful reagents to oxidize organic compounds. (1-10). Certain aldehydes can be oxidized to carboxylic acids with    3–60% aqueous H2O2 without organic solvents or metallic catalysts. Ignoring the ability of aqueous H2O2 to oxidize aldehydes, tremendous efforts have been made to develop metal-based catalysts (11-13) and inorganic (14) or organic promoters (15, 16) for the oxidation of aldehydes. In 1941, Späth found that H2O2 reacts with dodecanal to form a perhydrate, which decomposes slowly at 120°C to give dodecanoic acid (17). Since then aqueous H2O2 has been considered to have a weak ability to oxidize aldehydes. Some benzaldehyde derivatives can be converted to methyl benzoates with 31% H2O2 in methanol containing 38 mol% H2SO4 (18). And a patent claimed that 35% H2O2 in dioxane containing HBr oxidizes aldehydes to carboxylic acids (19). However, the gener ...