Question

What is the product of the reaction between Benzene and \(CH_3Cl\) in the presence of anhydrous \(AlCl_3\)?

• A. Toluene
• B. Phenol
• C. Chlorobenzene
• D. Benzaldehyde

Hint:

Friedel–Crafts alkylation introduces an alkyl group onto a benzene ring using a Lewis acid catalyst like \(AlCl_3\).

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
The reaction describes the treatment of an aromatic ring with an alkyl halide in the presence of a Lewis acid catalyst.
Step 2: Key Formula or Approach:
This is a Friedel-Crafts Alkylation reaction, which is a type of Electrophilic Aromatic Substitution (EAS).
Step 3: Detailed Explanation:
The reaction proceeds in three main steps:
1. Generation of Electrophile: The Lewis acid \(AlCl_3\) reacts with \(CH_3Cl\) to form a methyl carbocation (\(CH_3^+\)).
\[ CH_3Cl + AlCl_3 \rightarrow CH_3^+ + AlCl_4^- \]
2. Electrophilic Attack: The \(CH_3^+\) carbocation attacks the electron-rich benzene ring, forming an arenium ion intermediate.
3. Deprotonation: The \(AlCl_4^-\) ion removes a proton from the ring to restore aromaticity, yielding methylbenzene.
\[ C_6H_6 + CH_3Cl \xrightarrow{AlCl_3} C_6H_5CH_3 + HCl \]
The common name for methylbenzene is Toluene.
Step 4: Final Answer:
The product formed is Toluene.