Question

How is carbolic acid prepared from the given compounds :

Aniline

Answer 1

Aniline:-
When aniline (a primary aromatic amine) is treated with nitrous acid (NaNO₂ and HCl) under ice-cold conditions, it gives benzene diazonium salt. This process is called diazotization. The aqueous solution of the diazonium salt is hydrolyzed with dilute sulphuric acid to give phenol. The reaction can be shown as follows: