Which one of the following reagents is used in the Riemer Tiemann reaction?

Which reagent is used in Reimer-Tiemann reaction?

Reimer-Tiemann reaction introduces an aldehyde group on to the aromatic ring of phenol, ortho to the hydroxyl group. This reacrtion involves electrophilic aromatic subsititution. It is a general method for the synthesis of subsituted salicyladehydes as depiced below: Which one of the following reagents is used in the above reaction ?

Reimer-Tiemann reaction introduces an aldehyde group on to the aromatic ring of phenol, ortho to the hydroxyl group. This reacrtion involves electrophilic aromatic subsititution. It is a general method for the synthesis of subsituted salicyladehydes as depiced below: Which one of the following reagents is used in the above reaction ?