Given below are two statements :
Statement (I) : The NH₂ group in Aniline is ortho and para directing and a powerful activating group.
Statement (II) : Aniline does not undergo Friedel-Craft's reaction (alkylation and acylation).
In the light of the above statements, choose the most appropriate answer from the options given below :

Solution

Chemistry ma’am · 4 steps

Both are true: the lone pair that makes NH₂ so activating is exactly what ruins Friedel-Crafts.

1. Statement I. The nitrogen lone pair is pushed into the ring by resonance. This puts extra electron density at the ortho and para carbons, so -NH₂ is a strong activating, ortho and para directing group. Statement I is correct.
2. Lewis acid trap. Friedel-Crafts needs a Lewis acid catalyst such as AlCl₃. Aniline is a Lewis base, so its nitrogen gives its lone pair to AlCl₃ and forms a salt.

   C₆H₅NH₂ + AlCl₃ → C₆H₅N(+)H₂-A(-)lCl₃

3. Ring deactivated. Nitrogen now carries a positive charge and pulls electrons out of the ring. The ring becomes strongly deactivated, so alkylation and acylation do not take place. Statement II is correct.
4. So. Both statements are correct, which is option (a).

The idea to keep. A basic group like -NH₂ reacts with the Lewis acid catalyst first. The positively charged product deactivates the ring, so aniline gives no Friedel-Crafts reaction.

Answer from the NTA final answer key. Solution by PrepWiser.