Question

Write short notes on the following: Reimer-Tiemann's reaction

Hint:

Reimer-Tiemann reaction is an electrophilic substitution reaction introducing an aldehyde (-CHO) group into phenol.

Answer 1

Step 1: Reimer-Tiemann reaction is used to introduce a formyl (-CHO) group into phenol. 

Step 2: Reaction: \[ C_6H_5OH + CHCl_3 + NaOH \rightarrow o-\text{hydroxybenzaldehyde} + p-\text{hydroxybenzaldehyde} \] 

Step 3: The reaction mechanism involves the formation of a dichlorocarbene intermediate, which undergoes electrophilic substitution at the ortho- and para-positions of phenol.