Question

Salicylaldehyde is synthesized from phenol, when reacted with

• A. HCl, NaOH
• B. CO₂ , NaOH
• C. CCl₄ , NaOH
• D.

  

Answer 1

The Correct Option is D

The synthesis of salicylaldehyde from phenol can be achieved through the reaction of phenol with HCl and NaOH in a method known as the Reimer-Tiemann reaction. Here’s how the reaction proceeds:

Reimer-Tiemann Reaction: In this reaction, phenol is treated with chloroform in the presence of a strong base (usually NaOH) and HCl is used for the acidic work-up.

The phenol undergoes electrophilic substitution, resulting in the ortho- and para-formylation of the aromatic ring.

Reaction Overview: The reaction mechanism involves:

• Formation of a phenolate ion from phenol when treated with NaOH. The nucleophilic phenolate ion attacks the carbon of the chloroform molecule, followed by hydrolysis to yield salicylaldehyde.

Final Product: The final product is salicylaldehyde, which can be represented as follows:

\(\text{Phenol} + \text{Chloroform} \xrightarrow{\text{NaOH}} \text{Salicylaldehyde}\)