91Ó°ÊÓ

Certain substituents activate the benzene ring making it more reactive than the benzene ring. Several other substituents deactivate the ring making it less reactive than benzene.Groups like$\mathbf{-}{\mathbf{NO}}_2$ and $\mathbf{-}\mathbf{COOH}$are meta directing groups and deactivate the benzene ring. Groups like$\mathbf{-}{\mathbf{NH}}_2$ and $\mathbf{-}\mathbf{OH}$are ortho-para directing groups and activate the benzene ring.

(a)In this reaction, bromobenzene reacts with $HN{O}_3$and$H_{2}S{O}_4$to produce

1-bromo-2-nitrobenzene and 1-bromo-4-nitrobenzene. The reaction can be given as:

Reaction (a)

(b)In this reaction, nitrobenzene reacts with $B{r}_2$and$FeB{r}_3$to form

1-bromo-3-nitrobenzene. The reaction can be given as:

Reaction (b)

(c)In this reaction phenol reacts with chlorine to produce 2-chlorophenol and 4-chlorophenol as products. The reaction can be given as:

Reaction (c)

(d)In this reaction, aniline reacts with bromine to produce 2-bromoaniline and 4-bromoaniline as the products. The reaction can be given as:

Reaction (d)