Benzene & Derivatives

Benzene & Its Derivatives

(The class of compounds, which contains benzene or substituted derivative of benzene)

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.

Monosubstituted Benzene

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:

HYDROCARBONS

Toluene (Methylbenzene)	Cumene (Isopropylbenzene)	Ethylbenzene	Styrene (Vinylbenzene)
OTHER FUNCTIONAL GROUPS

Phenol (Hydroxybenzene)	Aniline (Aminobenzene)	Benzaldehyde	Benzoic Acid


Benzamide	Anisole	Bromobenzene	Methylbenzoate

Disubstituted Benzenes

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
2-Bromotoluene	3-Chloroaniline	3-Nitrobenzoic acid	2-Nitrobenzaldehyde
o-Bromotoluene	m-Chloroaniline	m-Nitrobenzoic acid	o-Nitrobenzaldehyde

If neither group imparts a special name, locate the groups & alphabetize.


1-Bromo-2-ethylbenzene	1-Bromo-2-nitrobenzene	1-Bromo-4-nitrobenzene
o-Bromoethylbenzene	o-Bromonitrobenzene	p-Bromonitrobenzene

Polysubstituted Benzenes

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
2-Bromo-4-chlorotoluene	3-Chloro-2-nitroaniline	1-Bromo-2,4-dinitrobenzene