Chemistry

Hydrocarbons (continued)


Aromatics (continued)

Nomenclature

To name aromatics that contain only one aromatic ring plus the alkyl group, we must number the ring starting with the simplest radical.

Then put in alphabetical order. The prefixes di, tri, tetra do not enter alphabetical order.


ethylbenzene


2-ethyl-1-methylbenzene

For two branches we use the radicals ortho (O), goal (m) and for (P).

The ortho (o) position is 1-2.
The goal position (m) is 1-3.
The position for (p) is 1-4.


                                       
           

o-xylene
o-dimethyl benzene
1,2-dimethyl benzene
m-xylene
m-dimethyl benzene
1,3-dimethyl benzene
p-xylene
p-dimethyl benzene
1,4-dimethyl benzene

Some condensed aromatics:


1-ethyl-3,7-dimethyl naphthalene


1,3,7-trimethyl naphthalene

Aromatic radicals

The groups derived from aromatic hydrocarbons that have lost an H are called a group. aril or arila. Can be represented by -Ar

Some arilas:

                

Phenyl, Benzyl, o-Toluil, m-Toluil, p-Toluil