Étard reaction

The Étard reaction is a chemical reaction that involves the direct oxidation of an aromatic or heterocyclic bound methyl group to an aldehyde using chromyl chloride. It is named for the French chemist Alexandre Léon Étard (5 January 1852, Alençon – 1 May 1910). For example, toluene can be oxidised to benzaldehyde:



Other oxidation reagents like potassium permanganate or potassium dichromate oxidize to the more stable carboxylic acids.