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

Abstract

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.

INTRODUCTION

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 ...