Reimer-Tiemann reaction

The Reimer-Tiemann reaction is a chemical reaction used for the ortho-formylation of phenols.



Reaction mechanism
Chloroform (1) reacts with strong base to form the chloroform carbanion (2), which will quickly alpha-eliminate to give dichlorocarbene (3). Dichlorocarbene will react in the ortho- and para- position of the phenate (5) to give the dichloromethyl substituted phenol (7). After basic hydrolysis, the desired product (9) is formed.