Question

The product formed in the below reaction is

• A. ortho-product
• B. meta-product
• C. para-product
• D. 2,4-dinitro product
• E. 3,4-dinitro product

Hint:

Substituents with a full positive charge on the atom directly attached to the ring, such as $-\text{NR}_3^+$, are always strong meta-directors.

Answer 1

The Correct Option is B

Concept: The direction of electrophilic aromatic substitution is governed by the nature of the substituent already present on the benzene ring.

Step 1: {Identify the nature of the substituent.} The substituent is a quaternary ammonium group, $-\text{N}^+(\text{CH}_3)_3$. This group carries a positive charge directly on the nitrogen atom attached to the ring.

Step 2: {Determine the electronic effect.} The positive charge makes the group strongly electron-withdrawing by the inductive effect ($-I$ effect). It lacks lone pairs, so it cannot provide resonance stabilization to the ring.

Step 3: {Predict the orientation of nitration.} Strongly electron-withdrawing groups without resonance capability are meta-directing and deactivating. Nitration using $\text{H}_2\text{SO}_4/\text{HNO}_3$ will therefore place the nitro group ($-\text{NO}_2$) at the meta position.