BITSAT2017ChemistryHaloalkanes and HaloarenesActual
Chlorobenzene → Reaction - ( X ) Phenol → Reaction - ( Y ) Salicylaldehyde . The reactions(s) X ' ' and Y ' ' respectively are
Options
- AFries rearrangement and Kolbe
- BCumene and Reimer-Tiemann
- CDow and Reimer-Tiemann
- DDow and Sandmeyer.
Correct answer
C. Dow and Reimer-Tiemann
Step-by-step solution
Phenol is manufactured by heating chlorobenzene with 10% aqueous NaOH solution at about 623K under 300 atm and in the presence of copper salt acting as a catalyst to form sodium phenoxide. The sodium salt when treated with dil. HCl, gives phenol. This method is known as Dow's process. When phenol is heated with CHCl 3 in the presence of aqueous NaOH, an aldehydic group (−CHO) get introduced in the ring at a position ortho to the phenolic group. This reaction is known as the Reimer-Tiemann reaction.