This can be
done by protecting the -NH2 group by acetylation with acetic
anhydride, then carrying out the desired substitution followed
by hydrolysis of the substituted amide to the substituted amine The lone pair of electrons on nitrogen of acetanilide  interacts
with oxygen atom due to resonance as shown below:
Rationalised 2023-24
273
Amines
Hence, the lone pair of electrons on nitrogen is less available for
donation to benzene ring by  resonance Therefore, activating
effect of –NHCOCH3 group is less than that of amino group (b) Nitration: Direct nitration of aniline yields tarry oxidation
products in addition to the nitro derivatives