Question

Find the product Z in the series of reactions. \[ \text{Phenol} \xrightarrow{\text{Zn dust}} X \xrightarrow{\text{CH}_3\text{Cl / anhyd. AlCl}_3} Y \xrightarrow{\text{alkaline KMnO}_4} Z \]

• A. benzaldehyde
• B. benzene
• C. benzoic acid
• D. benzophenone

Hint:

Any alkyl benzene on oxidation with KMnO$_4$ gives benzoic acid.

Answer 1

The Correct Option is C

Concept:
•Phenol + Zn dust → benzene
•Friedel-Crafts alkylation → alkyl benzene
•Strong oxidation (KMnO$_4$) → carboxylic acid

Step 1: \[ \text{Phenol} \xrightarrow{\text{Zn}} \text{Benzene (X)} \]

Step 2: \[ \text{Benzene} \xrightarrow{\text{CH}_3\text{Cl/AlCl}_3} \text{Toluene (Y)} \]

Step 3: \[ \text{Toluene} \xrightarrow{\text{KMnO}_4} \text{Benzoic acid (Z)} \] \[ \therefore Z = \text{benzoic acid} \]