Question

Chlorobenzene $\underset{X}{\overset{Reagent}{\to }}$ Phenol $\underset{Y}{\overset{Reagent}{\to }}$ Salicylaldehyde. $X$ and $Y$ reactions are respectively:

• A. Fries rearrangement and Kolbe-Schmidt
• B. Cumene and Reimer-Tiemann
• C. Dow and Reimer-Tiemann
• D. Dow and Friedal-Craft

Answer 1

The correct option is C Dow and Reimer-Tiemann

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 $CH{Cl}_3$ 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.