Question

how to distinguish between anisole and aniline​

Answer 1

Answer:

Aniline is a much stronger base than anisole, and so the strongly-acidic conditions used for most electrophilic aromatic substitution reactions convert the NH2NH2 group on aniline into NH+3NH3+, which is strongly deactivating.

In order to do conventional aromatic substitution on aniline, you must first acylate it. This makes the nitrogen far less basic, while keeping its activating, o,p-directing character.

(You can remove the acyl group by acid-catalyzed hydrolysis, afterwards.)

However, if a strong acid is not involved, aniline is far more active toward electrophilic substitution than anisole. You can brominate both anisole and aniline without a catalyst, just Br2Br2. But aniline brominates three times!