MHT CET Chemistry Question (2026) — Solution

Step-by-step solution

When phenol is treated with chloroform (CHCl_3) in the presence of aqueous sodium hydroxide (NaOH), an aldehyde group (-CHO) is introduced at the ortho position of the benzene ring. This reaction results in the formation of salicylaldehyde (2-hydroxybenzaldehyde) as the major product. This electrophilic substitution reaction, which proceeds via a dichlorocarbene (:CCl_2) intermediate, is known as the Reimer-Tiemann reaction. Answer: Reimer-Tiemann reaction