Question

The product X is :

• A.

  

• B.

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• C.

  

• D.

  

Hint:

Always protect \(-NH_2\) before halogenation → prevents polysubstitution.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Direct bromination of aniline leads to poly-substitution. Protecting the \( -\text{NH}_{2} \) group by acetylation reduces its activating power and allows controlled mono-substitution.
Step 2: Detailed Explanation:
1. Protection: p-Toluidine (\( \text{4-methylaniline} \)) reacts with acetic anhydride to form p-methylacetanilide. The amino group is protected as an acetamido group (\( -\text{NHCOCH}_{3} \)).
2. Bromination: In p-methylacetanilide, the acetamido group is ortho/para directing. Since the para position is already blocked by the methyl group, bromine will enter the ortho position relative to the acetamido group.
Product: 2-bromo-4-methylacetanilide.
3. Deprotection: Hydrolysis (\( \text{H}^{+}/\text{H}_{2}\text{O} \)) removes the acetyl group, regenerating the free amino group.
Product X: 2-bromo-4-methylaniline.
Step 3: Final Answer:
The product X is 2-bromo-4-methylaniline.