Oxidation of which of the following arenes does not give benzoic
acid

Options

A. Ethylbenzene
B. Cumene
C. Mesitylene
D. toluene

Answer

To determine which arene does not yield benzoic acid upon oxidation, we will analyze the oxidation reactions of the given arenes: ethyl benzene, cumene, mesitylene, and toluene.

### Step-by-Step Solution:

1. **Identify the Arenes**: The arenes we need to analyze are:
- Ethyl benzene
- Cumene (isopropyl benzene)
- Mesitylene (1,3,5-trimethylbenzene)
- Toluene

2. **Oxidation of Ethyl Benzene**:
- Ethyl benzene (C6H5-CH2-CH3) has a benzylic hydrogen that can be oxidized.
- When oxidized using KMnO4 and KOH (followed by dilute H2SO4), ethyl benzene forms benzoic acid (C6H5-COOH).
- **Conclusion**: Ethyl benzene gives benzoic acid.

3. **Oxidation of Cumene**:
- Cumene (C6H5-CH(CH3)2) also has a benzylic hydrogen.
- Upon oxidation, it similarly forms benzoic acid.
- **Conclusion**: Cumene gives benzoic acid.

4. **Oxidation of Mesitylene**:
- Mesitylene (C6H3(CH3)3) has three methyl groups attached to the benzene ring.
- Each methyl group can be oxidized to a carboxylic acid (COOH).
- Therefore, mesitylene will yield three molecules of benzoic acid upon oxidation.
- **Conclusion**: Mesitylene does not yield only benzoic acid; it gives three COOH groups.

5. **Oxidation of Toluene**:
- Toluene (C6H5-CH3) has a benzylic hydrogen.
- Upon oxidation, it forms benzoic acid.
- **Conclusion**: Toluene gives benzoic acid.

### Final Answer:
The arene that does not yield benzoic acid upon oxidation is **mesitylene**.