Consider the following reaction :
`C_(6)H_(5)-underset((R))underset(H) underset(|)overset(CH_(3)) overset(|)C-Cl+C_(2)H_(5)overset(o+)OtoC_(2)H_(5)O-underset(100% (S)"form") underset(H)underset(|)overset(CH_(3))overset(|)C-C_(6)H_(5)`
Which one of the following compounds will give SN2 reaction ?

Options

A. `CH_(3)-Br`
B. `CH_(3)-overset(Br)overset(|)(CH)-CH_(3)`
C. `C_(6)H_(5)-CH_(2)Cl`
D. All of these

Answer

To determine which compound will give an SN2 reaction, we need to analyze the structure of each compound and consider the conditions required for an SN2 mechanism.

### Step-by-Step Solution:

1. **Understanding SN2 Mechanism**:
- The SN2 (Substitution Nucleophilic Bimolecular) reaction involves a nucleophile attacking the electrophilic carbon atom from the opposite side of the leaving group (in this case, Cl). This results in a backside attack, which leads to the inversion of configuration at the carbon center.

2. **Identifying the Structure of Compounds**:
- We need to identify the structure of the compounds provided in the options. The compounds are:
- **Option 1**: CH3Br (Methyl bromide)
- **Option 2**: CH3CHBr (Ethyl bromide)
- **Option 3**: C6H5CH2Cl (Benzyl chloride)
- **Option 4**: All of the above

3. **Analyzing Each Compound**:
- **Option 1 (CH3Br)**: This is a methyl halide. Methyl halides are ideal for SN2 reactions because they are primary and have minimal steric hindrance.
- **Option 2 (CH3CHBr)**: This is a primary alkyl halide (ethyl bromide). Primary alkyl halides also favor SN2 reactions due to low steric hindrance.
- **Option 3 (C6H5CH2Cl)**: This is a benzyl chloride. Benzyl halides are also suitable for SN2 reactions because the benzyl carbon is primary and the aromatic ring does not introduce significant steric hindrance.
- **Option 4 (All of the above)**: Since all the compounds analyzed can undergo SN2 reactions, this option is also valid.

4. **Conclusion**:
- All the given compounds (methyl bromide, ethyl bromide, and benzyl chloride) can undergo SN2 reactions due to their primary nature and lack of steric hindrance. Therefore, the answer is **Option 4: All of the above**.