Target Exam

CUET

Subject

Chemistry

Chapter

Organic: Amines

Question:

The correct sequence for converting aniline to p-bromoaniline is

(A) $Br_2/CH_3COOH$
(B) Alkaline Hydrolysis
(C) $(CH_3CO)_2O$ and Pyridine
(D) Separation of ortho and para products

Arrange the above option from the sentence meaning. Choose the correct answer from the options given below:

Options:

(A), (B), (C), (D)

(A), (C), (B), (D)

(B), (C), (A), (D)

(C), (A), (D), (B)

Correct Answer:

(C), (A), (D), (B)

Explanation:

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.