Prehnitene or 1,2,3,4-tetramethylbenzene is an organic compound with the formula C6H2(CH3)4, classified as an aromatic hydrocarbon.

It is a flammable colorless liquid which is nearly insoluble in water but soluble in organic solvents.

Prehnitene is one of three isomers of tetramethylbenzene, the other two being isodurene (1,2,3,5-tetramethylbenzene) and durene (1,2,4,5-tetramethylbenzene).

[2] Industrially, prehnitene can be isolated from the reformed fraction of oil refineries.

It may also be produced by methylation of toluene, xylenes and the trimethylbenzenes hemimellitene and pseudocumene.