Question

nitration of amines is meta directing???

Answer 1

Amino group in aniline is ortho and para directing while aniline hydrogen chloride is meta directing.

This is because NH2 group in aniline is highly activating group.

A lone pair of electrons is present on N which releases the electron density to the benzene ring and hence activates the benzene ring towards electrophilic substitution reactions at ortho and para positions.

Answer 2

Amines are activating groups and donate electrons to the resonance structure using the lone pair of electrons on Nitrogen. But when aromatic amines are nitrated, for example when benzyl amine is nitrated, it gives a meta nitro benzyl amine. Given the activating nature of amine groups, shouldn't the compound be an ortho-para directing variant? I tried figuring it out. One explanation I've come up with is that when it's nitrated, the proton from the nitrous acid forms a coordinate covalent bond with the amine group closing the lone pair electron to the bond. As a result it becomes an NH3+ group. That would mean that it has a deactivating effect or electron withdrawing effect. That's why the incoming nitro groups are attached to the meta positions.