The amino group is ortho, para directing and a powerful activating group, so aryl amines undergo the typical electrophilic substitution reactions readily. In fact, the rate of these reactions is so great that in certain cases poly-substitution, rather than mono-substitution, occurs even under mild conditions. If the reaction has to be stopped at the mono-substitution stage, the activating effect of the –NH2 group has to be controlled.
Identify the product of the given reaction.
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → 2,4,6-Tribromoaniline
The –NH2 group is a powerful activating group and directs to the ortho and para positions. With bromine water, all three of these positions (2, 4 and 6) are brominated at room temperature, and a white precipitate forms:
\( \displaystyle \ce{C6H5NH2 + 3Br2} \xrightarrow{\ce{H2O}} \ce{C6H2Br3NH2 + 3HBr} \)
The product is 2,4,6-tribromoaniline.
Why the other options are incorrect
Option (1) 2-Bromoaniline — Incorrect. The ring is so reactive that substitution does not stop at one Br; a monobromo product needs the –NH2 group protected by acetylation first.
Option (2) 4-Bromoaniline — Incorrect. It is made through acetanilide (acetylation, bromination, hydrolysis), not from aniline and bromine water.
Option (3) 2,4-Dibromoaniline — Incorrect. The remaining ortho position (6) is also activated, so the third Br enters as well.
NCERT (2026-27 edition):
9.6 Chemical Reactions – “(a) Bromination: Aniline reacts with bromine water at room temperature to give a white precipitate of 2,4,6-tribromoaniline.”