Q9 P - Organic Chemistry (Mcmurry)

Question

Question: Predict the major products of the following reactions:

(a) Nitration of bromobenzene

 (b) Bromination of nitrobenzene

(c) Chlorination of phenol 

(d) Bromination of aniline

Step-by-Step Solution

Answer

a.

b.

c.

d.

Step1: Substituent Effects in Electrophilic Substitution

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.

Step 2: Predicting the major products of the reaction

(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)