Chapter 16.SE, Problem 47AP

Interpretation Introduction

a) Bromobenzene

Interpretation:

The major product(s) formed when bromobenzene is nitrated is to be given. Whether it will react faster or slower than benzene is also to be stated.

Concept introduction:

Monosubstituted benzenes can be nitrated using a mixture of Conc. HNO₃ and H₂SO₄. Electron releasing substituent groups, excep halogens, activate the ring and direct the incoming electrophile to the o- and p-positions. Compounds with these substituent groups are more reactive than benzene. Halogens are o- and p-directors but they deactivate the ring. Hence halobenzenes are less reactive than benzene. Electron withdrawing substituent groups deactivate the ring and direct the incoming electrophile to the m-position. Compounds with these substituent groups are less reactive than benzene.

To give:

The major products formed when bromobenzene is nitrated and to state whether it will react faster or slower than benzene.

Answer to Problem 47AP

The major products formed when bromobenzene is nitrated are o-bromonitrobenzene and p-bromonitrobenzene.

Bromobenzene will react slower than benzene.

Explanation of Solution

Bromine is an o- and p-directing group. It also has considerable electron withdrawing inductive effect which deactivates the ring. Hence bromobenzene is less reactive than benzene.

Conclusion

The major products formed when bromobenzene is nitrated are o-bromonitrobenzene and p-bromonitrobenzene.

Bromobenzene will react slower than benzene.

Interpretation Introduction

b) Benzonitrile

Interpretation:

The major product(s) formed when benzonitrile is nitrated is to be given. Whether it will react faster or slower than benzene is also to be stated.

Concept introduction:

Monosubstituted benzenes can be nitrated using a mixture of Conc. HNO₃ and H₂SO₄. Electron releasing substituent groups, except halogens, activate the ring and direct the incoming electrophile to the o- and p-positions. Compounds with these substituents are more reactive than benzene. Halogens are o- and p-directors but they deactivate the ring. Hence halobenzenes are less reactive than benzene. Electron withdrawing substituent groups deactivate the ring and direct the incoming electrophile to the m-position. Compounds with these substituents are less reactive than benzene.

To give:

The major products formed when benzonitrile is nitrated and to state whether it will react faster or slower than benzene.

Answer to Problem 47AP

The major product formed when benzonitrile is nitrated is m-nitrobenzonitrile.

Benzonitrile will react slower than benzene.

Explanation of Solution

The cyanide group is strongly electron withdrawing in nature. Hence it is a meta director. The attraction of electrons away from the ring reduces the electron density in the ring. Thus benzonitrile reacts slower than benzene.

Conclusion

The major product formed when benzonitrile is nitrated is m-nitrobenzonitrile.

Benzonitrile will react slower than benzene.

Interpretation Introduction

c) Benzoic acid

Interpretation:

The major product(s) formed when benzoic acid is nitrated is to be given. Whether it will react faster or slower than benzene is also to be stated.

Concept introduction:

Monosubstituted benzenes can be nitrated using a mixture of Conc. HNO₃ and H₂SO₄. Electron releasing substituent groups, except halogens, activate the ring and direct the incoming electrophile to the o- and p-positions. Compounds with these substituents are more reactive than benzene. Halogens are o- and p-directors but they deactivate the ring. Hence halobenzenes are less reactive than benzene. Electron withdrawing substituent groups deactivate the ring and direct the incoming electrophile to the m-position. Compounds with these substituents are less reactive than benzene.

To give:

The major products formed when benzoic acid is nitrated and to state whether it will react faster or slower than benzene.

Answer to Problem 47AP

The major product formed when benzoic acid is nitrated is m-nitrobenzoic acid.

Benzoic acid will react slower than benzene.

Explanation of Solution

The C=O in carboxyl group is strongly electron withdrawing in nature. Hence it is a meta director. The attraction of electrons away from the ring reduces the electron density in the ring. Thus benzoic acid reacts slower than benzene.

Conclusion

The major product formed when benzoic acid is nitrated is m-nitrobenzoic acid.

Benzoic acid will react slower than benzene.

Interpretation Introduction

d) Nitrobenzene

Interpretation:

The major product(s) formed when nitrobenzene is nitrated is to be given. Whether it will react faster or slower than benzene is also to be stated.

Concept introduction:

Monosubstituted benzenes can be nitrated using a mixture of Conc. HNO₃ and H₂SO₄. Electron releasing substituent groups, except halogens, activate the ring and direct the incoming electrophile to the o- and p-positions. Compounds with these substituents are more reactive than benzene. Halogens are o- and p-directors but they deactivate the ring. Hence halobenzenes are less reactive than benzene. Electron withdrawing substituent groups deactivate the ring and direct the incoming electrophile to the m-position. Compounds with these substituents are less reactive than benzene.

To give:

The major products formed when nitrobenzene is nitrated and to state whether it will react faster or slower than benzene.

Answer to Problem 47AP

The major product formed when nitrobenzene is nitrated is m-dinitrobenzene.

Nitrobenzene will react slower than benzene.

Explanation of Solution

The nitro group is strongly electron withdrawing in nature. Hence it is a meta director. The attraction of electrons away from the ring reduces the electron density in the ring. Thus nitrobenzene reacts slower than benzene.

Conclusion

The major product formed when nitrobenzene is nitrated is m-dinitrobenzene.

Nitrobenzene will react slower than benzene.

Interpretation Introduction

e) Benzenesulfonic acid

Interpretation:

The major product(s) formed when benzenesulfonic acid is nitrated is to be given. Whether it will react faster or slower than benzene is also to be stated.

Concept introduction:

Monosubstituted benzenes can be nitrated using a mixture of Conc. HNO₃ and H₂SO₄. Electron releasing substituent groups, except halogens, activate the ring and direct the incoming electrophile to the o- and p-positions. Compounds with these substituents are more reactive than benzene. Halogens are o- and p-directors but they deactivate the ring. Hence halobenzenes are less reactive than benzene. Electron withdrawing substituent groups deactivate the ring and direct the incoming electrophile to the m-position. Compounds with these substituents are less reactive than benzene.

To give:

The major products formed when benzenesulfonic acid is nitrated and to state whether it will react faster or slower than benzene.

Answer to Problem 47AP

The major product formed when benzenesulfonic acid is nitrated is m-nitro benzenesulfonic acid.

Benzenesulfonic acid will react slower than benzene.

Explanation of Solution

The sulfonic acid group is strongly electron withdrawing in nature. Hence it is a meta director. The attraction of electrons away from the ring reduces the electron density in the ring. Thus benzenesulfonic acid reacts slower than benzene.

Conclusion

The major product formed when benzenesulfonic acid is nitrated is m-nitro benzenesulfonic acid.

Benzenesulfonic acid will react slower than benzene.

Interpretation Introduction

f) Methoxybenzene

Interpretation:

The major product(s) formed when methoxybenzene is nitrated is to be given. Whether it will react faster or slower than benzene is also to be stated.

Concept introduction:

Monosubstituted benzenes can be nitrated using a mixture of Conc. HNO₃ and H₂SO₄. Electron releasing substituent groups, except halogens, activate the ring and direct the incoming electrophile to the o- and p-positions. Compounds with these substituents are more reactive than benzene. Halogens are o- and p-directors but they deactivate the ring. Hence halobenzenes are less reactive than benzene. Electron withdrawing substituent groups deactivate the ring and direct the incoming electrophile to the m-position. Compounds with these substituents are less reactive than benzene.

To give:

The major products formed when methoxybenzene is nitrated and to state whether it will react faster or slower than benzene.

Answer to Problem 47AP

The major products formed when methoxybenzene is nitrated are o-nitromethoxybenene and p-nitromethoxybenene.

Methoxybenzene will react faster than benzene.

Explanation of Solution

The methoxy group is electron releasing in nature. Hence it is an o- and p-director. The attraction of electrons towards the ring increases the electron density in the ring. Thus methoxybenzene reacts faster than benzene.

Conclusion

The major products formed when methoxybenzene is nitrated are o-nitromethoxybenene and p-nitromethoxybenene.

Methoxybenzene will react faster than benzene.