(a) Bromination: Aniline reacts with bromine water at room
temperature to give a white precipitate of 2,4,6-tribromoaniline The main problem encountered during electrophilic substitution
reactions of aromatic amines is that of their very high reactivity Substitution tends to occur at ortho- and para-positions If we
have to prepare monosubstituted  aniline derivative, how can
the activating effect of –NH2 group be controlled