Organic Chemistry: Concepts and Applications - Headley Allan D. 2020
Carbon Functional Groups and Organic Nomenclature
2.8 Structure and Nomenclature of Substituted Benzenes
Benzene, which has the chemical formula C6H6, is a unique compound and Chapter 17 is dedicated to the study of benzene. Figure 2.7 shows different representations of the structure of benzene.
Figure 2.7. Representations of benzene.
Substituted benzene results from the substitution of a hydrogen for a group that we have discussed earlier and examples are shown below.
2.8.1 Nomenclature of Disubstituted Benzenes
If there are two substituents bonded to the benzene ring, the exact relationship between the substituents on the ring must be specified. The numbering system is similar to that of cyclohexane in that the name should have the lowest possible number combination, as shown in the example below.
Note that when there are more than one substituents on the benzene ring, they are listed in an alphabetical order.
Problem 2.16
i. Give the structures of each of the following compounds.
1. 1,2-Dibromobenzene
2. 3-Chlorophenol
3. 1-Fluoro-4-nitrobenzene.
ii. Give the names for each of the following compounds.
If benzene is a substituent, it is named as the phenyl group (─C6H5) in the nomenclature of the molecule, as shown in the example below.
