Which of the following steps is not correct in the mechanism of electrophilic substitution of benzene?

Options

A. Generation of electrophile like `X^(+),R^(+),RC^(+)O,NO_(2)^(+),`etc.
B. Attack of electrophile resulting in the formation of arenium ion in which one of the carbon is `sp^(3)` hybridised.
C. Addition of proton on benzene ring to give carbocation.
D. Removal of proton from `sp^(3)` carbon atom to restore aromatic character.

Explanation

To determine which step is not correct in the mechanism of electrophilic substitution of benzene, we need to analyze the steps involved in this reaction. The electrophilic substitution mechanism generally includes the following steps:

### Step-by-Step Solution:

1. **Formation of Electrophile**:
- In this step, an electrophile is generated from a reactant. For instance, in the case of methyl chloride (CH3Cl) reacting with aluminum chloride (AlCl3), the AlCl3 acts as a Lewis acid and coordinates with the chlorine atom in CH3Cl. This results in the formation of a methyl cation (CH3+) and AlCl4-.
- **Hint**: Look for the generation of an electrophile from a reactant in the mechanism.

2. **Electrophilic Attack on Benzene**:
- The generated electrophile (in this case, CH3+) attacks the benzene ring. This attack leads to the formation of a sigma complex (also known as an arenium ion), where one of the carbon atoms in the benzene ring becomes sp3 hybridized due to the attachment of the electrophile.
- **Hint**: Identify the step where the electrophile interacts with the benzene ring.

3. **Formation of Carbocation**:
- After the electrophile has attacked the benzene ring, a carbocation intermediate is formed. This carbocation is stabilized by resonance with the remaining pi system of the benzene ring.
- **Hint**: Check if the intermediate formed is correctly identified as a carbocation.

4. **Restoration of Aromaticity**:
- To restore the aromaticity of the benzene ring, a proton (H+) is removed from the sp3 hybridized carbon. This results in the reformation of the pi bond and the aromatic character of the ring.
- **Hint**: Look for the step that discusses the removal of a proton to regain aromaticity.

5. **Regeneration of Catalyst**:
- Finally, the proton (H+) that was removed can react with AlCl4- to regenerate AlCl3 and produce HCl as a byproduct.
- **Hint**: Identify the step that involves the regeneration of the catalyst and the formation of byproducts.

### Incorrect Step Identification:
From the analysis, the statement that is incorrect in the mechanism is the one that claims the formation of a "uranium ion" during the electrophilic attack. The correct term should be "carbocation" rather than "uranium ion."

### Conclusion:
The incorrect statement in the mechanism of electrophilic substitution of benzene is the claim that an "uranium ion" is formed. Instead, a carbocation is formed during this process.