Question

Write notes on 

(a) Kolbe’s reaction 

(b) Reimer-Tiemann reaction

Answer 1

(a) Kolbe’s reaction:

When Sodium phenoxide is heated with CO₂ at 400 K and under a pressure 6-7 atm, sodium salicylate is obtained. This on hydrolysis gives orthohydroxy benzoic acid or salicylic acid.

Reimer – Tiemman reaction: When phenol is heated with CHCI₃ at 340 K, o-hydroxy benzaldehyde or salicylaldehyde is obtained.