Chapter 15.SE, Problem 20AP

Interpretation Introduction

a) Dinitrobenzene

Interpretation:

The possible isomers for dinitrobenzene are to be drawn and their names are to be given.

Concept introduction:

Disubstituted benzenes can exist as three isomers such as ortho, meta and para. They are named using the prefixes ortho (o), meta (m) and para (p). An ortho-disubstituted benzene has its two substituent groups in a 1,2-relationship on the ring. A meta-disubstituted benzene has its two substituent groups in a 1,3-relationship on the ring. A para-disubstituted benzene has its two substituent groups in a 1,4-relationship on the ring. While writing the name the substituent groups are arranged alphabetically.

To draw:

The possible isomers for dinitrobenzene and to name them.

Interpretation Introduction

b) Bromodimethylbenzene

Interpretation:

The possible isomers for bromodimethylbenzene are to be drawn and their names are to be given.

Concept introduction:

Trisubstitutedbenzenes can exist as six isomers with the three substituents in 1,2,3; 1,2,4; 1,2,5; 1,2,6; 1,3,4 and 1,3,5 relationship.

Benzene with more than two substituent groups are named choosing a point of attachment as carbon 1 and numbering the substituent groups on the ring so that the second substituent has as low number as possible. If ambiguity still exists, numbering is done such that the third and fourth substituent groups have a number as low as possible, until a point of difference is obtained. While writing the name the substituent groups are arranged alphabetically.

To draw:

The possible isomers for bromodimethylbenzene and to name them.

Interpretation Introduction

c) Trinitrophenol

Interpretation:

The possible isomers for trinitrophenol are to be drawn and their names are to be given.

Concept introduction:

Trinitrophenol can exist as six isomers with the four substituents in 1,2,3,4; 1,2,3,5; 1,2,3,6; 1,2,4,5; 1,2,4,6 and 1,3,4,5 relationship.

Benzene with more than two substituent groups are named choosing a point of attachment as carbon 1 and numbering the substituent groups on the ring so that the second substituent has as low number as possible. If ambiguity still exists, numbering is done such that the third and fourth substituent groups have a number as low as possible, until a point of difference is obtained. While writing the name the substituent groups are arranged alphabetically.

To draw:

The possible isomers for trinitrophenol and to name them.