Consider the following sequence of reactions :
`C_6H_5CH_3overset(Cl_2)rarrp-ClC_6H_4CH_3overset(NBS)rarr(X) overset(Mg)rarr(Y)overset((i)"ethylene oxide")rarr(Z) `
Final product (Z) is

Options

A. `p - ClC_6H_4CH_2CH_2OH`
B. `p- ClC_6H_4CH_2CH_2CH_2OH`
C. `p-(HOCH_2CH_2) - C_6H_4CH_2Br`
D. `p - (HOCH_2CH_2)-C_6H_4CH_3`

Answer

To solve the problem step by step, we will analyze each reaction in the sequence provided and determine the final product (Z).

### Step 1: Chlorination of Toluene
- **Reaction**: Toluene (C₆H₅CH₃) reacts with chlorine (Cl₂).
- **Mechanism**: Toluene is an aromatic compound with a methyl group (–CH₃) that is ortho-para directing. Chlorination will predominantly occur at the para position due to steric hindrance at the ortho position.
- **Product**: The major product formed is para-chlorotoluene (p-ClC₆H₄CH₃).

### Step 2: Bromination with NBS
- **Reaction**: para-Chlorotoluene reacts with N-bromosuccinimide (NBS).
- **Mechanism**: NBS facilitates benzylic bromination, which occurs at the benzylic position (the carbon adjacent to the aromatic ring).
- **Product**: The product formed is p-ClC₆H₄CH₂Br (compound X).

### Step 3: Formation of Grignard Reagent
- **Reaction**: Compound X (p-ClC₆H₄CH₂Br) reacts with magnesium (Mg).
- **Mechanism**: The reaction of an alkyl halide with magnesium forms a Grignard reagent.
- **Product**: The product formed is p-ClC₆H₄CH₂MgBr (compound Y).

### Step 4: Reaction with Ethylene Oxide
- **Reaction**: Compound Y (p-ClC₆H₄CH₂MgBr) reacts with ethylene oxide (C₂H₄O).
- **Mechanism**: The Grignard reagent acts as a nucleophile and attacks the electrophilic carbon in ethylene oxide, leading to ring opening and formation of a new carbon-carbon bond.
- **Product**: The product formed is p-ClC₆H₄CH₂CH₂CH₂O⁻MgBr (compound Z).

### Step 5: Hydrolysis of the Grignard Reagent
- **Reaction**: Compound Z undergoes hydrolysis.
- **Mechanism**: Hydrolysis of the Grignard reagent involves the addition of water (H₂O) to convert the alkoxide into an alcohol.
- **Final Product**: The final product formed is p-ClC₆H₄CH₂CH₂CH₂OH (compound Z).

### Conclusion
The final product (Z) is para-chlorobutanol, specifically p-ClC₆H₄CH₂CH₂CH₂OH.

### Answer
The final product (Z) is **p-Chlorobutanol**.

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