Identify the correct reagent for Etard reaction

The correct reagent for the Etard Reaction is Chromyl chloride. This reaction is an important chemical process for oxidizing aromatic methyl groups into aldehydes.

Detailed Explanation

The Etard Reaction is named after the French chemist Alexandre Léon Étard. This mechanism involves the use of chromyl chloride (CrO₂Cl₂) as a reagent to selectively oxidize aromatic methyl groups or methyl groups attached to heterocyclic compounds into aldehydes.

For example, when toluene is subjected to the Etard Reaction, it undergoes oxidation to form benzaldehyde. This reaction is particularly significant in organic synthesis for its ability to selectively convert methyl groups into aldehydes without further oxidation to carboxylic acids.

Explanation for Incorrect Options

Since chromyl chloride is the specific reagent required for the Etard Reaction, other options such as A, C, and D are incorrect. These reagents do not facilitate the selective oxidation of aromatic methyl groups into aldehydes as the Etard Reaction does.

Conclusion

Therefore, the correct answer is Option B: Chromyl chloride. The Etard Reaction is a vital method in organic chemistry for producing aldehydes from aromatic methyl groups with high specificity.