Question

Write the reaction involved in Reimer-Tiemann reaction.

Hint:

Reimer-Tiemann = Phenol + Chloroform \(\rightarrow\) Salicylaldehyde.
If $CCl_4$ is used instead of $CHCl_3$, Salicylic acid is formed.

Answer 1

Step 1: Understanding the Concept:
The Reimer-Tiemann reaction is used to introduce an aldehyde group (\( -CHO \)) at the ortho position of the phenol ring.
Step 2: Detailed Explanation:
When phenol is treated with chloroform (\( CHCl_3 \)) in the presence of sodium hydroxide, a substituted benzaldehyde (salicylaldehyde) is formed.
The intermediate is a dichlorocarbene (\( :CCl_2 \)) which acts as an electrophile.
Chemical Equation:
\[ C_6H_5OH + CHCl_3 + 3NaOH \xrightarrow{340K} \text{o-}HOC_6H_4CHO + 3NaCl + 2H_2O \]
The main product is 2-Hydroxybenzaldehyde (Salicylaldehyde).
Step 3: Final Answer:
The reaction yields salicylaldehyde as the major product.