Which of the following will not show coupling reaction with benzenediazonium chloride?

Options

A. Aniline
B. Phenol
C. 2-Naphthol
D. Benzyl alcohol

Explanation

To determine which compound will not show a coupling reaction with benzenediazonium chloride, we need to analyze the nature of the compounds provided and their ability to act as nucleophiles in the presence of benzenediazonium chloride.

### Step-by-Step Solution:

1. **Understanding Benzenediazonium Chloride**:
- Benzenediazonium chloride (BDC) is a strong electrophile. It can react with nucleophiles to form azo compounds through a coupling reaction.

2. **Identifying Nucleophiles**:
- Compounds that can act as nucleophiles typically contain electron-rich sites, such as -NH2 (amino group), -OH (hydroxyl group), or other groups that can donate electrons.

3. **Analyzing the Given Compounds**:
- **Aniline (C6H5NH2)**: Contains an amino group (-NH2), which is a strong nucleophile. It will couple with BDC.
- **Phenol (C6H5OH)**: Contains a hydroxyl group (-OH), which can also act as a nucleophile. It will couple with BDC.
- **Naphthol (C10H7OH)**: Similar to phenol, naphthol has a hydroxyl group and can couple with BDC.
- **Benzyl Alcohol (C6H5CH2OH)**: Contains a hydroxyl group, but the -CH2- group is less nucleophilic compared to the -OH in phenol or naphthol. Benzyl alcohol does not effectively participate in coupling reactions with BDC.

4. **Conclusion**:
- Among the compounds listed, benzyl alcohol will not show a coupling reaction with benzenediazonium chloride because it does not act as a strong nucleophile.

### Final Answer:
Benzyl alcohol will not show a coupling reaction with benzenediazonium chloride.