Assertion (A): Benzoic acid does not undergo Friedel – Crafts reaction. Reason (R): Carboxyl group is deactivating and the catalyst aluminium chloride gets bonded to the carboxyl group.
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Electron-withdrawing groups such as carboxyl groups deactivate the aromatic ring, preventing Friedel – Crafts reactions.
Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of the Assertion (A).
Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
Assertion (A) is true, but Reason (R) is false.
Assertion (A) is false, but Reason (R) is true.
Show Solution
The Correct Option isA
Solution and Explanation
- Assertion (A) is correct: Benzoic acid does not undergo Friedel–Crafts reactions owing to the deactivating influence of the carboxyl group. - Reason (R) is also accurate: The carboxyl group (-COOH) is electron-withdrawing, deactivating the aromatic ring and reducing its reactivity towards electrophilic substitution, including Friedel–Crafts reactions.
Step 1: The carboxyl group in benzoic acid deactivates the aromatic ring, inhibiting reaction with electrophiles.
Step 2: The catalyst, AlCl$_3$, cannot interact with the deactivated ring for the Friedel–Crafts reaction to proceed.
