In an aqueous solution containing sodium bicarbonate, aniline reacts quickly with bromine to give 2, 4, 6-tribromoaniline. Nitration of aniline requires very strong conditions, however, and the yields (mostly m-nitroaniline) are poor.
(a) What conditions are used for nitration, and what form of aniline is present under these conditions?
(b) Explain why nitration of aniline is so sluggish and why it gives mostly meta substitution.
(c) Although nitration of aniline is slow and gives mostly meta substitution, nitration of acetanilide (PhNHCOCH3) goes quickly and gives mostly para substitution. Use resonance forms to explain this difference in reactivity