Chapter 2.14, Problem 3QQ

Interpretation Introduction

Interpretation:

The correct name for the given compound has to be chosen from the given set of options..

Concept Introduction:

When hydrogen atoms are replaced by one or more groups in benzene is known as substitution reaction and the compounds produced is benzene derivatives.

Benzene derivative with one substituent:

IUPAC system of naming monosubstituted benzene derivatives uses the name of substituent as prefix to the name benzene. If the group that is present in benzene cannot be named easily means, then the benzene ring is often treated as group attached to this substituent. The benzene ring is known as phenyl in this approach.

Benzene derivative with two substituents:

When benzene ring contains two substituents it is known as disubstituted benzene derivative. Three isomers are possible for the disubstituted benzene derivative. The prefix used in IUPAC name are,

Ortho- means disubstitution in 1,2

Meta- means disubstitution in 1,3

Para- means disubstitution in 1,4

When both the substituents present on the benzene ring imparts a special name, where all the substituents are cited in alphabetical order before the ending –benzene. The carbon that bears the group with alphabetical priority is given number 1.

Benzene derivatives with three or more substituents:

More than two groups are present in the benzene ring means, their positions are numbered. The numbering is always done in a way that the carbon atom bearing substituent gets the lowest numbering possible. If there is a choice of numbering system, then the group that comes alphabetically first is given the lowest number.