Chapter 16.10, Problem 22P

Interpretation Introduction

a) m-Chloronitrobenzene.

Interpretation:

How to synthesize m-chloronitrobenzene from benzene is to be shown.

Concept introduction:

In aromatic electrophilic substitution reactions the nitro group is meta directing. Since a meta chloronitrobenzene is to be synthesized, benzene is first nitrated and the nitrobenzene obtained is then chlorinated.

To show:

How to synthesize m-chloronitrobenzene from benzene.

Interpretation Introduction

b) m-Chloroethylbenzene.

Interpretation:

How to synthesize m-chloroethylbenzene from benzene is to be shown.

Concept introduction:

Since a meta halogen substituted alkyl benzene is to be synthesized benzene is first converted into a meta directing ketone by Friedal-Crafts acylation. The ketone upon halogenation will yield m-halogen substituted ketone which can be reduced to get the desired product.

To show:

How to synthesize m-chloroethylbenzene from benzene.

Interpretation Introduction

c) 4-Chloro-1-nitro-2-propylbenzene.

Interpretation:

How to synthesize 4-chloro-1-nitro-2-propylbenzene from benzene is to be shown.

Concept introduction:

Since a propyl benzene with a nitro group in the ortho position and a Cl at meta position is to be synthesized. Benzene is first converted into a meta directing ketone by Friedal-Crafts acylation. The ketone upon halogenation will yield a m-halogen substituted ketone which can be reduced to a m-chloroalkyl benzene. Alkyl groups are o- and p- directing. Hence by nitrating the m-chloroalkyl benzene the desired product can be synthesized.

To show:

How to synthesize 4-chloro-1-nitro-2-propylbenzene from benzene.

Interpretation Introduction

d) 3-Bromo-2-methylbenzenesulfonic acid.

Interpretation:

How to synthesize 3-bromo-2-methylbenzenesulfonic acid from benzene is to be shown.

Concept introduction:

A benzenesulfonic acid with a methyl group in the ortho position and a Br at the meta position is to be synthesized. Benzene is first converted into toluene by Friedal-Crafts alkylation. The toluene upon sulfonation will yield a methyl sulfonic acid. By brominating the methylsulfonic acid the desired product can be synthesized.

To show:

How to synthesize 3-bromo-2-methylbenzenesulfonic acid from benzene.