Question

Toluene reacts with a halogen in the presence of iron (III) chloride giving ortho and para compounds. The reaction is:

• A. Electrophilic addition reaction
• B. Electrophilic substitution reaction
• C. Free radical substitution reaction
• D. Nucleophilic substitution reaction

Hint:

Always look at the substituent that is already attached to the benzene ring to figure out whether the incoming electrophile will attach itself at the ortho/para position, or the meta position, and this depends on the group’s ability to donate or withdraw electron density via resonance or induction.

Answer 1

The Correct Option is B

Toluene undergoes electrophilic substitution with halogens, catalyzed by the Lewis acid \(FeCl_{3}\). Toluene's electron-donating methyl group activates the ortho and para positions for this substitution. The reaction mechanism involves:
An electrophile is generated \((e.g., Cl^{+}) by FeCl_{3}\).
The electrophile attacks the activated positions.
The intermediate carbocation is stabilized, followed by the restoration of aromaticity.
This reaction is characteristic of aromatic compounds.