Question

Among the following, the reaction that proceeds through an electrophilic substitution, is:

• A.
• B.
• C.
• D.

Answer 1

The Correct Option is B

To determine which reaction proceeds through an electrophilic substitution mechanism, we need to understand what electrophilic substitution is. Electrophilic substitution reactions are characteristic of aromatic compounds such as benzene and its derivatives. In these reactions, an electrophile replaces an atom, usually a hydrogen, on an aromatic ring.

Consider each reaction option to identify signs of electrophilic substitution:

1. Option A: Benzene reacting with a strong electrophile, such as a halogen. This is a typical electrophilic aromatic substitution (e.g., halogenation, nitration).
2. Option B: A methyl group adding to benzene is also indicative of an electrophilic substitution reaction like Friedel-Crafts alkylation. This is the correct answer.
3. Option C: If an electrophilic addition mechanism is involved rather than substitution, this would be incorrect.
4. Option D: If any non-aromatic electrophilic reaction is given, such as nucleophilic substitution or addition, exclude it.

Therefore, the correct reaction that proceeds through an electrophilic substitution mechanism is found in Option B, which involves the addition of a methyl group to the benzene ring:

The reasoning includes that this type of reaction typically involves the use of reagents like alkyl halides and catalyst (e.g., AlCl₃) to facilitate the reaction, commonly known as Friedel-Crafts alkylation.