PYQ NEET- Aldehydes Ketones And Carboxylic Acids L-2

Question: The oxidation of toluene to benzaldehyde by chromyl chloride is called#

A) Etard reaction

B) Riemer–Tiemann reaction

C) Wurtz reaction

D) Cannizzaro’s reaction

Answer: Etard reaction#

Sol:#

The oxidation of toluene $\left(\mathrm{C}_6 \mathrm{H}_5 \mathrm{CH}_3\right)$ with chromyl chloride $\left(\mathrm{CrO}_2 \mathrm{Cl}_2\right)$ in $\mathrm{CCl}_4$ or $\mathrm{CS}_2$ to give benzaldehyde is called Etard reaction. In this reaction, the chromyl chloride first forms a brown complex, which is separated and then decomposed with $\mathrm{H}_2 \mathrm{O}$ to give benzaldehyde $\left(\mathrm{C}_6 \mathrm{H}_5 \mathrm{CHO}\right)$.