4-Ethyltoluene

4-Ethyltoluene is an organic compound with the formula CH₃C₆H₄C₂H₅. It is one of three isomers of ethyltoluene, the other two isomers being 3-ethyltoluene and 2-ethyltoluene. All are colorless liquids and all are used for the production of specialty polystyrenes.

4-Ethyltoluene

Names
Preferred IUPAC name 1-Ethyl-4-methylbenzene
Other names p-Ethylmethylbenzene, p-Ethyltoluene
Identifiers
CAS Number	622-96-8 Y
3D model (JSmol)	Interactive image
ChemSpider	11660
ECHA InfoCard	100.009.784
PubChem CID	12160
UNII	G6JY83VLB5 Y
CompTox Dashboard (EPA)	DTXSID9029194
InChI InChI=1S/C9H12/c1-3-9-6-4-8(2)5-7-9/h4-7H,3H2,1-2H3 Key: JRLPEMVDPFPYPJ-UHFFFAOYSA-N
SMILES CCc1ccc(cc1)C
Properties
Chemical formula	C9H12
Molar mass	120.195 g·mol−1
Appearance	colorless liquid
Density	0.861 g/cm3
Boiling point	162 °C (324 °F; 435 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Production and use

Ethyltoluene is produced by ethylation of toluene:

CH₃C₆H₅ + C₂H₄ → CH₃C₆H₄C₂H₅

Over typical acid catalysts, this process gives a mixture of the 2-, 3-, and 4- isomers. Using a modified zeolite catalyst, the alkylation is shape-selective for the 4- isomer.^[1]

4-Ethyltoluene is subjected dehydrogenation to give 4-vinyltoluene.^[2]