Benzene & Its Derivatives
(The class of compounds, which contains benzene or substituted derivative of benzene)
There is a class of hydrocarbons, that is characterized by a high degree of unsaturation and unusual stability. The most important and common member of this class is benzene (C6H6). The formula is represented in several ways:
Expanded structural formula with condensed line angle formula.
This representation is not as common in chemistry references, but is often found in biological & biochemistry.
When one of the positions on the ring has been substituted with another atom or group of atoms, the compound is a monosubstituted benzene. If two positions are replaced, then it's a disubstituted, & so on. Many of the monosubstituted compounds have their own name and some of the more common ones are listed in the Table below:
|OTHER FUNCTIONAL GROUPS|
When two of the positions on the ring has been substituted with another atom or group of atoms, the compound is a disubstituted benzene. There is a separate nomenclature to describe the relative positions. Using toluene as the example, the ortho orientation is the 1,2 relationship; the meta is 1,3 and the para is 1,4. Note that there are two ortho and meta positions, but only one para.
Where one group imparts a special name, name the compound as a derivative of that molecule:
|Toluene is the parent name||Aniline is the parent name||Benzoic acid is the parent name||Benzaldehyde is the parent name|
If neither group imparts a special name, locate the groups & alphabetize.
If one group imparts a special name, name the molecule as a derivative of that compound and if no group imparts a special name, list them in alphabetical order, giving them the lowest set of numbers
|Toluene is the parent name||Aniline is the parent name||No special name|
EXERCISE: Write the IUPAC name for each of the following structures.
END OF SECTION
email questions & comments to: Dr. JA Colapret