Question

The presence of \[\ce{-NO2}\] group at ortho or para position increases the reactivity of haloarenes towards nucleophilic substitution reactions. Give reason to explain the above statement.

Answer 1

Because the nitro group delocalises the negative charge more, the presence of the nitro group in the ortho or para position boosts the reactivity. Alternatively, the nitro group at the ortho or para position removes electron density from the benzene ring, making the nucleophile attack easier. Resonance and the \[\ce{NO2}\] group stabilise the carbanion that is created.