`"Phenol "overset(NaNO_(2)//H_(2)SO_(4))rarr B overset(H_(2)O)rarr C overset(NaOH)rarr D`
Name of the above reaction is

Options

A. Liebermann's reaction
B. Phthalein fusion test
C. Reimer - Tiemann rection
D. Schotten - Baumann reaction

Answer

To determine the name of the reaction involving phenol and its subsequent transformations, we will analyze each step of the reaction sequence provided in the question.

### Step-by-Step Solution:

1. **Reaction of Phenol with Sodium Nitrite and Concentrated Sulfuric Acid**:
- When phenol (C6H5OH) reacts with sodium nitrite (NaNO2) in the presence of concentrated sulfuric acid (H2SO4), it forms a nitroso derivative known as para-nitrosophenol (B).
- The reaction can be summarized as:
\[ \text{C}_6\text{H}_5\text{OH} + \text{NaNO}_2 + \text{H}_2\text{SO}_4 \rightarrow \text{C}_6\text{H}_4\text{(NO)}\text{OH} + \text{HSO}_4^- \]

2. **Hydrolysis of Para-Nitrosophenol**:
- The product B (para-nitrosophenol) then reacts with water (H2O) to yield a compound known as phenol endophenol (C).
- This reaction can be represented as:
\[ \text{C}_6\text{H}_4\text{(NO)}\text{OH} + \text{H}_2\text{O} \rightarrow \text{C}_6\text{H}_5\text{(OH)} + \text{HNO} \]

3. **Reaction of Phenol Endophenol with Sodium Hydroxide**:
- Finally, phenol endophenol (C) reacts with sodium hydroxide (NaOH) to form the sodium salt of phenol endophenol (D).
- The reaction can be summarized as:
\[ \text{C}_6\text{H}_5\text{(OH)} + \text{NaOH} \rightarrow \text{C}_6\text{H}_5\text{(O}^-\text{)}\text{Na}^+ + \text{H}_2\text{O} \]

4. **Conclusion**:
- The entire reaction sequence described is known as **Lieberman's Reaction**. This reaction is characterized by the formation of a nitroso derivative from phenol, followed by hydrolysis and subsequent formation of a sodium salt.

### Final Answer:
The name of the above reaction is **Lieberman's Reaction**.