The electrophilic aromatic substitution of a compound `C_(6)H_(5)Y` produces mainly a meta-disubstituted product. Among the following which one could be the substituent `Y` ?

Options

A. `-N(CH_(3))_(2)`
B. `-COOH`
C. `-CH_(3)`
D. `-OCH_(3)`

Answer

To solve the question regarding the electrophilic aromatic substitution of the compound \( C_6H_5Y \) that produces mainly a meta-disubstituted product, we need to analyze the nature of the substituent \( Y \).

### Step-by-Step Solution:

1. **Understanding Electrophilic Aromatic Substitution**:
- Electrophilic aromatic substitution involves an electrophile attacking the aromatic ring, replacing one of the hydrogen atoms. The position where the electrophile attacks depends on the nature of the substituent already attached to the ring.

2. **Identifying the Role of Substituent \( Y \)**:
- Substituents can be classified as either electron-donating groups (EDGs) or electron-withdrawing groups (EWGs).
- EDGs increase electron density at the ortho and para positions, leading to ortho and para substitution.
- EWGs decrease electron density at the ortho and para positions, making the meta position more favorable for electrophilic attack.

3. **Determining the Type of Substituent \( Y \)**:
- Since the question states that the substitution produces mainly a meta-disubstituted product, \( Y \) must be an electron-withdrawing group.
- Examples of electron-withdrawing groups include nitro (\(-NO_2\)), cyano (\(-CN\)), and carboxylic acid (\(-COOH\)).

4. **Analyzing the Given Options**:
- We need to examine the provided options to identify which substituent \( Y \) is an electron-withdrawing group.
- If the options include groups like methyl (\(-CH_3\)), methoxy (\(-OCH_3\)), and carboxylic acid (\(-COOH\)), we can classify them:
- Methyl and methoxy are EDGs (ortho-para directing).
- Carboxylic acid (\(-COOH\)) is an EWG (meta directing).

5. **Conclusion**:
- The only substituent \( Y \) that would lead to a meta-disubstituted product in the electrophilic aromatic substitution reaction is the carboxylic acid group (\(-COOH\)).
- Therefore, the answer is option **B** (\(-COOH\)).