Etard Reactions
The oxidation of aromatic methyl groups to aldehydes with cromyl chloride (CrO2Cl2) is known as Etard reaction.
In this reaction cromyl chloride (CrO2Cl2) forms a complex with the hydrocarbon, which is decomposed into aldehyde by treatment with water.A solution of cromyl chloride in carbon disulphide is carefully added to hydrocarbon at room temperature.The addition product thus formed is decomposed to give the aldehyde , which is removed by distillation to avoid further reaction.
In polymethyl compounds onl one methyl group is oxidised under normal conditions
