Which of the following intermediate is formed in Reimer-Teimann reaction ?

Options

A. Carbocation
B. Carbanion
C. Carbene
D. Free radical

Answer

To solve the question regarding the intermediate formed in the Reimer-Tiemann reaction, we can follow these steps:

### Step 1: Understand the Reimer-Tiemann Reaction
The Reimer-Tiemann reaction involves the treatment of phenol with chloroform (CHCl3) in the presence of a strong base, typically sodium hydroxide (NaOH). This reaction leads to the formation of ortho-hydroxybenzaldehyde (salicylaldehyde).

**Hint:** Familiarize yourself with the general conditions and reactants involved in the Reimer-Tiemann reaction.

### Step 2: Identify the Key Reactants
The key reactants in this reaction are:
- Phenol (C6H5OH)
- Chloroform (CHCl3)
- Sodium hydroxide (NaOH)

**Hint:** Recognize the role of each reactant in the reaction mechanism.

### Step 3: Mechanism Overview
The mechanism begins with the generation of an electrophile. The hydroxide ion (OH-) attacks chloroform, leading to the formation of dichlorocarbene (CCl2), which is a key intermediate in this reaction.

**Hint:** Understand how electrophiles are generated in organic reactions.

### Step 4: Formation of the Intermediate
The reaction proceeds as follows:
1. The hydroxide ion attacks chloroform, resulting in the formation of dichlorocarbene (CCl2).
2. This intermediate then reacts with phenol to form an intermediate compound that eventually leads to salicylaldehyde after further reactions.

**Hint:** Focus on the structure of the intermediate formed during the reaction.

### Step 5: Identify the Final Product
After the reaction and subsequent steps, the final product is salicylaldehyde (2-hydroxybenzaldehyde). However, the question specifically asks for the intermediate, which is dichlorocarbene.

**Hint:** Differentiate between the intermediate and the final product in a reaction mechanism.

### Conclusion
The intermediate formed in the Reimer-Tiemann reaction is **dichlorocarbene (CCl2)**.