Which of the following compounds react slower than benzene in electrophilic substitution?

Options

A.
B.
C.
D.

Explanation

To determine which compounds react slower than benzene in electrophilic substitution reactions, we need to analyze the nature of the substituents attached to the benzene ring.

### Step-by-Step Solution:

1. **Understand Electrophilic Substitution**:
- Electrophilic substitution reactions involve the replacement of a hydrogen atom in the benzene ring with an electrophile. The reactivity of benzene in these reactions is influenced by the substituents on the ring.

2. **Identify the Role of Substituents**:
- Substituents can either be electron-donating or electron-withdrawing.
- Electron-donating groups (like -OH, -NH2) increase the electron density on the benzene ring, making it more nucleophilic and thus more reactive.
- Electron-withdrawing groups (like -NO2, -CN) decrease the electron density on the benzene ring, making it less nucleophilic and thus less reactive.

3. **Analyze Each Compound**:
- **Compound with -NO2 (Nitro group)**: This is an electron-withdrawing group. It pulls electron density away from the benzene ring, making it less nucleophilic and thus slower to react than benzene.
- **Compound with -OH (Hydroxyl group)**: This is an electron-donating group. It increases the electron density on the benzene ring, making it more reactive than benzene.
- **Compound with -NH2 (Amino group)**: This is also an electron-donating group. It similarly increases the electron density on the benzene ring, making it more reactive than benzene.
- **Compound with -X (Halogen)**: Halogens can be considered as weakly electron-withdrawing due to their electronegativity, but they also have lone pairs that can donate electron density. However, their overall effect is still to activate the ring slightly, making them more reactive than benzene.

4. **Conclusion**:
- Among the compounds analyzed, the one with the -NO2 group is the only substituent that makes the benzene ring less reactive than benzene itself. Therefore, it reacts slower than benzene in electrophilic substitution.

### Final Answer:
The compound that reacts slower than benzene in electrophilic substitution is the one with the -NO2 (Nitro group).

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