When phenol is treated with chloroform (CHCl3) in presence of sodium hydroxide (NaOH) to produce salicylaldehyde ( ortho Hydroxybenzaldehyde) is known as Reimer Tiemann,s Reaction.
This reaction is actually formylation (Addition of -CHO group) of phenol at ortho position.
![](https://chemigod.com/wp-content/uploads/2024/02/image-38.png?w=1024)
Short Mechanism:-
![](https://chemigod.com/wp-content/uploads/2024/02/image-40.png?w=1024)