Pentamethylbenzene
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Preferred IUPAC name 1,2,3,4,5-Pentamethylbenzene | |||
Other names Pentamethylbenzene | |||
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ECHA InfoCard | 100.010.763 ![]() | ||
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Properties | |||
Chemical formula | C11H16 | ||
Molar mass | 148.249 g·mol−1 | ||
Density | 0.917 g/cm3 | ||
Melting point | 54.4 °C (129.9 °F; 327.5 K) | ||
Boiling point | 232 °C (450 °F; 505 K) | ||
Solubility in organic solvents | soluble | ||
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Main hazards | Flammable | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). ![]() ![]() ![]() Infobox references |
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
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
- ^ 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 978-3527306732.
- ^ 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.
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