Write the reaction involved in the following:
Reimer-Tiemann reaction
Reimer-Tiemann reaction
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Solution and Explanation
The Reimer-Tiemann reaction introduces a \(-CHO\) group at the ortho position of phenol using chloroform and a base.
Step 1:
Phenol is treated with chloroform (\(CHCl_3\)) in the presence of aqueous \(NaOH\) (at about 340 K). The dichlorocarbene generated attacks the ring at the ortho position to give an intermediate that on hydrolysis forms salicylaldehyde.
Step 2:
Reaction: \(C_6H_5OH + CHCl_3 + 3NaOH \rightarrow\) 2-hydroxybenzaldehyde (salicylaldehyde) \(+ 3NaCl + 2H_2O\).
Answer: Phenol reacts with \(CHCl_3\) and aqueous \(NaOH\) to give salicylaldehyde (2-hydroxybenzaldehyde) after acidification. \(C_6H_5OH \xrightarrow{CHCl_3,\ NaOH\ then\ H^+}\ o\text{-}HO\text{-}C_6H_4\text{-}CHO\).
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