In which of the following reactions phenol is not obtained:

Options

A.
B.
C.
D.

Answer

To determine in which of the following reactions phenol is not obtained, we will analyze each reaction step by step.

### Step 1: Analyze the Reaction with Salicylic Acid
1. **Starting Material**: Salicylic acid reacts with NaOH and CaO.
2. **First Step**: The salicylic acid reacts with NaOH to form sodium salicylate (sodium phenoxide) and water.
3. **Decarboxylation**: The sodium salicylate undergoes decarboxylation when heated with soda lime (NaOH + CaO).
4. **Final Product**: After decarboxylation and acidification with dilute HCl, phenol is obtained.

**Conclusion**: Phenol is obtained from this reaction.

### Step 2: Analyze the Reaction with Grignard Reagent
1. **Starting Material**: Grignard reagent reacts with water.
2. **Hydrolysis**: The Grignard reagent undergoes hydrolysis, leading to the formation of a benzene ring and magnesium hydroxide bromide (MgOHBr).
3. **Final Product**: No phenol is formed in this reaction; instead, a benzene derivative is produced.

**Conclusion**: Phenol is not obtained from this reaction.

### Step 3: Analyze the Reaction with Chlorobenzene
1. **Starting Material**: Chlorobenzene reacts with NaOH under high temperature and pressure (Dows process).
2. **Reaction Conditions**: The reaction leads to the formation of sodium phenoxide and the removal of NaCl and water.
3. **Final Product**: Upon acidification with dilute HCl, phenol is obtained.

**Conclusion**: Phenol is obtained from this reaction.

### Step 4: Analyze the Reaction with Benzene Diazonium Chloride
1. **Starting Material**: Benzene diazonium chloride reacts with water.
2. **Hydrolysis**: The diazonium salt undergoes hydrolysis in the presence of dilute acid (H2SO4 or HCl).
3. **Final Product**: This reaction yields phenol along with nitrogen gas and hydrochloric acid.

**Conclusion**: Phenol is obtained from this reaction.

### Final Answer
Based on the analysis, the reaction in which phenol is not obtained is the one involving the **Grignard reagent**.