The tetramethylbenzenes constitute a group of substances of aromatic hydrocarbons, which structure consists of a benzene ring with four methyl groups (âÂÂCH<sub>3</sub>) as a substituent. Through their different arrangement, they form three structural isomers with the molecular formula C<sub>10</sub>H<sub>14</sub>. They also belong to the group of C<sub>4</sub>-benzenes. The best-known isomer is durene.