The correct sequence for converting aniline to p-bromoaniline is (A)…

The correct answer is Option (4) → (C), (A), (D), (B)

To convert aniline → p-bromoaniline, the correct strategy is protection → bromination → separation → deprotection.
The correct sequence for converting aniline to p-bromoaniline is (C) → (A) → (D) → (B).

Direct bromination of aniline gives 2,4,6-tribromoaniline because $-NH_2$ is a very strong activating, ortho/para directing group.

So we first protect $-NH_2$ by acetylation, then brominate selectively, then hydrolyze back to $-NH_2$.

 

1. (C) (CH₃CO)₂O and Pyridine — Acetylation
   Aniline is first acetylated to form acetanilide. This protects the –NH₂ group and prevents excessive bromination.

2. (A) Br₂ / CH₃COOH — Bromination
   Bromination of acetanilide gives mainly para-bromoacetanilide (with some ortho product).

3. (D) Separation of ortho and para products
   The para isomer is separated because it is the desired compound.

4. (B) Alkaline Hydrolysis — Deacetylation
   Finally, hydrolysis removes the acetyl protecting group to yield p-bromoaniline.