Cymene describes organic compounds with the formula . Three isomers exist: 1,2- 1,3-, and 1,4-. All are colorless liquids, immiscible in water, with similar boiling points. They are classified are aromatic hydrocarbons. The bearing two substituents: an isopropyl group and a methyl group.[1]
| Cymenes | ||||
| Name | p-Cymene | |||
|---|---|---|---|---|
| Structural formula | ||||
| CAS number | 527-84-4 | 535-77-3 | 99-87-6 | |
| melting point | -71.54 | -63.75 | -67.94 | |
| boiling point (°C) | 178.15 | 175.05 | 177.10 | |
m- and p-Cymene are prepared by alkylation of toluene with propylene:
These alkylations are catalyzed by various Lewis acids, such as aluminium trichloride.
m- and p-Cymene are mainly of interest as precursors to the respective cresols, which exploits the Hock rearrangements.[1]