Question

Which of the following reacts with phenol to give salicyladehyde after hydrolysis?

• A. Dichloro methane
• B. Trichloro methane
• C. Methyl chloride
• D. None of the above

Answer 1

The correct option is B Trichloro methane

When phenol gets converted to salicylaldehyde in the presence of $CHC{l}_3+Aq.NaOH$ followed by hydrolysis, the reaction is known as Reimer-Tiemann reaction. It is an electrophilic substitution reaction, reaction intermediate dichloro carbene is formed and acts as an electrophile. Hence, the correct answer will be trichloro methane.


Mechanism:
The mechanism of Riemer-Tiemann reaction involves 3 steps.

Step-1:
Formation of carbene

Step-2:
Formation of intermediate

Step-3:
Hydrolysis of intermediate