the reaction of `C_6H_5O^(-)Na^(+) and CO_2` at 6 atm 400 K, followed by addition of aq.acid is called

Options

A. Reimer - Tiemann reaction
B. Kolbe reaction
C. Wurtz reaction
D. Cannizzaro reaction

Answer

To solve the question regarding the reaction of sodium phenoxide (C₆H₅O⁻Na⁺) with carbon dioxide (CO₂) at 6 atm and 400 K, followed by the addition of aqueous acid, we can break it down into the following steps:

### Step-by-Step Solution:

1. **Identify the Reactants**: The reactants in this reaction are sodium phenoxide (C₆H₅O⁻Na⁺) and carbon dioxide (CO₂). Sodium phenoxide is formed by the reaction of phenol with sodium hydroxide (NaOH).

**Hint**: Remember that sodium phenoxide is a phenol derivative where the hydroxyl group (–OH) is replaced by a sodium ion (Na⁺).

2. **Reaction Conditions**: The reaction takes place under high pressure (6 atm) and elevated temperature (400 K). These conditions are crucial for facilitating the reaction between sodium phenoxide and CO₂.

**Hint**: High pressure and temperature can increase the reactivity of the reactants, promoting the formation of products.

3. **Reaction Mechanism**: When sodium phenoxide reacts with CO₂, it undergoes carboxylation. The carboxyl group (–COOH) is introduced at the ortho position relative to the existing hydroxyl group on the phenolic ring.

**Hint**: The ortho position is the position adjacent to the hydroxyl group on the benzene ring.

4. **Hydrolysis Step**: After the reaction with CO₂, the product is hydrolyzed by adding aqueous acid (H₃O⁺). This step converts the intermediate product into salicylic acid (2-hydroxybenzoic acid).

**Hint**: Hydrolysis involves the addition of water, which helps in converting the intermediate into a stable carboxylic acid.

5. **Final Product**: The final product of this reaction sequence is salicylic acid (C₇H₆O₃), which is characterized by having both a hydroxyl group and a carboxylic acid group on the benzene ring.

**Hint**: Salicylic acid is commonly known and is used in various applications, including as a precursor for aspirin.

6. **Name of the Reaction**: The entire process described is known as the **Kolbe's Electrolysis** or **Kolbe's Reaction**. It specifically refers to the carboxylation of sodium phenoxide to form salicylic acid.

**Hint**: Kolbe's Reaction is a well-known reaction in organic chemistry, particularly in the synthesis of carboxylic acids from phenolic compounds.

### Conclusion:
The reaction of sodium phenoxide with CO₂ at high pressure and temperature, followed by hydrolysis with aqueous acid, is called the **Kolbe's Reaction**.