Pentamethylbenzene
- 700-12-9 checkY
- H6JLD3AI98 checkY
- InChI=1S/C11H16/c1-7-6-8(2)10(4)11(5)9(7)3/h6H,1-5H3Key: BEZDDPMMPIDMGJ-UHFFFAOYSA-N
- InChI=1/C11H16/c1-7-6-8(2)10(4)11(5)9(7)3/h6H,1-5H3Key: BEZDDPMMPIDMGJ-UHFFFAOYAT
- Cc1cc(C)c(C)c(C)c1C
Pentamethylbenzene is an organic compound with the formula C6H(CH3)5. It is a colourless solid with a sweet odor. The compound is classified as an aromatic hydrocarbon. It is a relatively easily oxidized benzene derivative, with E1/2 of 1.95 V vs NHE.[1]
Synthesis and reactions
[edit ]It is obtained as a minor product in the Friedel–Crafts methylation of xylene to durene (1,2,4,5-tetramethylbenzene).[2] Like durene, pentamethylbenzene is rather electron-rich and undergoes electrophilic substitution readily.[3] Indeed, it is used as a scavenger for carbocations.[4]
Pentamethylbenzene has been observed as an intermediate in the formation of hexamethylbenzene from phenol [5] and alkylation of durene or pentamethylbenzene has been reported as a suitable starting material for the synthesis of hexamethylbenzene.[2]
References
[edit ]- ^ Howell, J. O.; Goncalves, J. M.; Amatore, C.; Klasinc, L.; Wightman, R. M.; Kochi, J. K. (1984). "Electron transfer from aromatic hydrocarbons and their pi-complexes with metals. Comparison of the standard oxidation potentials and vertical ionization potentials". Journal of the American Chemical Society. 106 (14): 3968–3976. doi:10.1021/ja00326a014.
- ^ a b Smith, Lee Irvin (1930). "Durene". Organic Syntheses . 10: 32. doi:10.15227/orgsyn.010.0032 ; Collected Volumes, vol. 2, p. 248.
- ^ Griesbaum, Karl; Behr, Arno; Biedenkapp, Dieter; Voges, Heinz-Werner; Garbe, Dorothea; Paetz, Christian; Collin, Gerd; Mayer, Dieter; Höke, Hartmut (2002). "Hydrocarbons". Ullmann's Encyclopedia of Industrial Chemistry . Weinheim: Wiley-VCH. doi:10.1002/14356007.a13_227. ISBN 978-3-527-30673-2.
- ^ Okaya, Shun; Okuyama, Keiichiro; Okano, Kentaro; Tokuyama, Hidetoshi (2016). "Trichloroboron-Promoted Deprotection of Phenolic Benzyl Ether Using Pentamethylbenzene as a Non Lewis-Basic Cation Scavenger". Organic Syntheses . 93: 63–74. doi:10.15227/orgsyn.093.0063 .
- ^ Landis, Phillip S.; Haag, Werner O. (1963). "Formation of Hexamethylbenzene from Phenol and Methanol". Journal of Organic Chemistry . 28 (2): 585. doi:10.1021/jo01037a517.