Ortho salicylic acid is frequently used as precursor for the preparation of Asprin. Which of the following reactions can be used to prepare o- salicylic acid from phenol

Options

A.
B.
C.
D.

Explanation

To prepare ortho-salicylic acid from phenol, we can utilize the Reimer-Tiemann reaction. Here’s a step-by-step breakdown of the process:

### Step 1: Identify the starting material
- The starting material for this reaction is **phenol** (C6H5OH).

### Step 2: Understand the Reimer-Tiemann reaction
- The Reimer-Tiemann reaction involves the reaction of phenol with chloroform (CHCl3) in the presence of a strong base, typically sodium hydroxide (NaOH).

### Step 3: Set up the reaction conditions
- The reaction conditions require:
- **Chloroform (CCl3)**
- **Sodium hydroxide (NaOH)**
- **Heat** (often applied to facilitate the reaction)

### Step 4: Reaction mechanism
1. **Formation of dichlorocarbene**:
- Chloroform reacts with sodium hydroxide to generate dichlorocarbene (CCl2).

2. **Electrophilic attack**:
- The dichlorocarbene acts as an electrophile and attacks the ortho position of the phenol ring, leading to the formation of an intermediate compound.

3. **Hydrolysis**:
- The intermediate undergoes hydrolysis, where the dichlorocarbene is replaced by a hydroxyl group (-OH), resulting in the formation of ortho-salicylic acid.

### Step 5: Final product
- The final product of this reaction is **ortho-salicylic acid** (2-hydroxybenzoic acid), which has both a hydroxyl group (-OH) and a carboxylic acid group (-COOH) on the benzene ring.

### Conclusion
- Therefore, the reaction that can be used to prepare ortho-salicylic acid from phenol is the Reimer-Tiemann reaction involving phenol, sodium hydroxide, and chloroform.