Question

Intermediate of above reaction is :

• A. $:CC{l}_2$
• B. $:CHCl$
• C. $\stackrel{+}{C}HC{l}_2$
• D. $\stackrel{+}{C}C{l}_3$

Answer 1

The correct option is A $:CC{l}_2$

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 is option (a).


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