In Friedel Crafts synthesis of `C_(6)H_(5)-CH_(3)`, reactants in addition of anhydrous aluminium chloride are :

Options

A. `C_(6)H_(6)+CH_(4)`
B. `C_(6)H_(6)+CH_(3)-Cl`
C. `C_(6)H_(5)Cl+CH_(3)-Cl`
D. `C_(6)H_(5)-Cl+CH_(4)`

Explanation

To synthesize toluene (C₆H₅-CH₃) using the Friedel-Crafts alkylation method, we need to identify the reactants required in addition to anhydrous aluminum chloride (AlCl₃). Here’s the step-by-step solution:

### Step 1: Identify the Target Compound
The target compound is toluene, which has the molecular formula C₆H₅-CH₃. This indicates that we need a benzene ring (C₆H₅) and a methyl group (CH₃).

### Step 2: Determine the Reactants
In Friedel-Crafts synthesis, we need:
- A benzene ring as the aromatic compound.
- An alkyl halide to provide the alkyl group (in this case, the methyl group).

### Step 3: Choose the Alkyl Halide
The appropriate alkyl halide for introducing a methyl group is methyl chloride (CH₃Cl). This compound can donate a methyl group during the reaction.

### Step 4: Role of Anhydrous Aluminum Chloride
Anhydrous aluminum chloride (AlCl₃) acts as a Lewis acid in this reaction. It helps in generating a more reactive electrophile from the alkyl halide (CH₃Cl).

### Step 5: Reaction Mechanism
1. **Formation of Electrophile**: The AlCl₃ interacts with CH₃Cl, forming a methyl cation (CH₃⁺) and AlCl₄⁻.
2. **Electrophilic Attack**: The methyl cation (CH₃⁺) acts as an electrophile and attacks the benzene ring, leading to the formation of a sigma complex.
3. **Deprotonation**: The sigma complex then loses a proton (H⁺), restoring the aromaticity of the benzene ring and yielding toluene (C₆H₅-CH₃).

### Step 6: Final Products
The final products of the reaction are:
- Toluene (C₆H₅-CH₃)
- Hydrogen chloride (HCl)
- Aluminum chloride (AlCl₃) as a byproduct.

### Conclusion
Thus, the reactants needed in addition to anhydrous aluminum chloride for the Friedel-Crafts synthesis of toluene are:
- Benzene (C₆H₆)
- Methyl chloride (CH₃Cl)