Phenol `overset(C_(6)H_(5)N_(2)^(+)Cl)underset(alkali solution) to ` Major Product : Product will be:

Options

A.
B.
C.
D.

Answer

To solve the problem, we need to identify the major product formed when phenol reacts with benzene diazonium chloride in an alkaline solution. Here’s a step-by-step breakdown of the reaction:

### Step 1: Identify the Reactants
We have two main reactants:
- **Phenol (C6H5OH)**: A compound with a hydroxyl (-OH) group attached to a benzene ring.
- **Benzene diazonium chloride (C6H5N2+Cl-)**: A diazonium salt, which contains a positively charged diazonium group (N2+) and a chloride ion (Cl-).

### Step 2: Understand the Reaction Conditions
The reaction occurs in a weak alkaline solution, typically with a pH between 9 to 10. This environment is essential for the reaction to proceed effectively.

### Step 3: Mechanism of the Reaction
In the alkaline solution, the hydroxyl group of phenol can act as a nucleophile. The diazonium salt can undergo a coupling reaction with phenol. The chloride ion (Cl-) is a leaving group in this reaction.

### Step 4: Formation of the Product
During the reaction:
1. The diazonium group (N2+) from benzene diazonium chloride attacks the para position of the phenol ring.
2. The Cl- ion and a hydrogen ion (H+) from phenol are eliminated, leading to the formation of a new compound.

The resulting product from this coupling reaction is **4-hydroxyazobenzene** (C6H5-N=N-C6H4(OH)), which is characterized by the azo (-N=N-) linkage between the two aromatic systems.

### Step 5: Final Product Identification
The major product formed is **4-hydroxyazobenzene**, which is an orange-colored dye commonly used in various applications.

### Summary of the Reaction
The overall reaction can be summarized as:
\[ \text{C}_6\text{H}_5\text{OH} + \text{C}_6\text{H}_5\text{N}_2^+\text{Cl}^- \rightarrow \text{C}_6\text{H}_5\text{N}=\text{N}-\text{C}_6\text{H}_4\text{OH} + \text{HCl} \]