Reimer-Tiemann reaction introduces an aldehyde group, on to the aromatic ring of phenol, ortho to the hydroxyl group. This reaction involves electrophilic aromatic substitution. This is a general method for the synthesis of substituted salicyladehydes as depicted below.
The structure of the intermediate I is
(A)(see structure)
(B)(see structure)✓ Correct
(C)(see structure)
(D)(see structure)
Answer: (B)
Solution
After dichlorocarbene (:CCl₂) attacks the ortho position of the phenoxide ring, the intermediate formed has the dichloromethyl group attached to the ring. The intermediate I is an ortho-substituted phenoxide with a -CHCl₂ group. This structure shows the phenoxide oxygen (O⁻) and the dichloromethyl substituent at the ortho position, which upon hydrolysis and further reaction yields the aldehyde group in the final product.
JEE Advanced · 2007 · 08 Apr 2007 · Paper 2 · Single correct option
