Question

The compound that is most reactive towards electrophilic nitration is

• A. Option 1
• B. Option 2
• C. Option 3
• D. Option 4 \bigskip

Hint:

For electrophilic substitution: Activating groups: \[ -CH_3,\ -OH,\ -NH_2 \] Deactivating groups: \[ -NO_2,\ -COOH,\ -CHO,\ -SO_3H \] More electron density means faster nitration.

Answer 1

The Correct Option is A

Concept: Electrophilic substitution reactions become faster when the aromatic ring contains electron-donating groups. Electron-donating groups increase electron density in the benzene ring and stabilize the intermediate carbocation. Electron-withdrawing groups decrease electron density and reduce reactivity.

Step 1: Examine the effect of the methyl group.
In toluene, the methyl group shows \[ +I \text{ effect} \] and hyperconjugation. These effects increase electron density in the ring. Hence toluene is more reactive than benzene.

Step 2: Examine the effect of the carboxyl group.
The group \[ -COOH \] shows strong electron-withdrawing effects. Therefore benzoic acid is less reactive than benzene.

Step 3: Examine the effect of the nitro group.
The nitro group \[ -NO_2 \] is one of the strongest deactivating groups. Nitrobenzene undergoes nitration very slowly.

Step 4: Compare all compounds.
Order of reactivity: \[ \text{Toluene} > \text{Benzene} > \text{Benzoic acid} > \text{Nitrobenzene} \] Therefore the most reactive compound is \[ \boxed{\text{Toluene}} \] \[ \boxed{\text{Option (A)}} \]