{{chembox |Verifiedimages = changed |Watchedfields = changed |verifiedrevid = 443812488 |ImageFile_Ref = {{chemboximage|correct|??}} |ImageFile = Durene.png |ImageSize = 120px |ImageAlt = Skeletal formula of durene |ImageFile1 = Durene 3D ball.png |ImageSize1 = 160px |ImageAlt1 = Ball-and-stick model of the durene molecule |PIN = 1,2,4,5-Tetramethylbenzene |OtherNames =Durol |Section1={{Chembox Identifiers |ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} |ChemSpiderID = 6999 |KEGG_Ref = {{keggcite|correct|kegg}} |KEGG = C14534 |InChI = 1/C10H14/c1-7-5-9(3)10(4)6-8(7)2/h5-6H,1-4H3 |InChIKey = SQNZJJAZBFDUTD-UHFFFAOYAJ |StdInChI_Ref = {{stdinchicite|correct|chemspider}} |StdInChI = 1S/C10H14/c1-7-5-9(3)10(4)6-8(7)2/h5-6H,1-4H3 |StdInChIKey_Ref = {{stdinchicite|correct|chemspider}} |StdInChIKey = SQNZJJAZBFDUTD-UHFFFAOYSA-N |CASNo_Ref = {{cascite|correct|CAS}} |CASNo = 95-93-2 |PubChem =7269 |UNII_Ref = {{fdacite|correct|FDA}} |UNII = 181426CFYB |ChEBI_Ref = {{ebicite|correct|EBI}} |ChEBI = 38978 |SMILES = c1c(c(cc(c1C)C)C)C }} |Section2={{Chembox Properties |Formula =C<sub>10</sub>H<sub>14</sub> |MolarMass =134.21816 |Density =0.868 g/cm<sup>3</sup> |MeltingPtC = 79.2 |BoilingPtC = 192 |BoilingPt_notes = at 760mmHg |MagSus = −101.2·10<sup>−6</sup> cm<sup>3</sup>/mol }} |Section3={{Chembox Hazards |MainHazards = Flammable |FlashPtC = 73.9 }} }}
'''Durene''', or '''1,2,4,5-tetramethylbenzene''', is an organic compound with the formula C<sub>6</sub>H<sub>2</sub>(CH<sub>3</sub>)<sub>4</sub>. It is a colourless solid with a sweet odor. The compound is classified as an alkylbenzene. It is one of three isomers of tetramethylbenzene, the other two being prehnitene (1,2,3,4-tetramethylbenzene) and isodurene (1,2,3,5-tetramethylbenzene). Durene has an unusually high melting point (79.2 °C), reflecting its high molecular symmetry.
==Production== It is a component of coal tar and was first prepared from pseudocumene in 1870.<ref>{{cite journal|first1 = Paul|last1 = Jannasch|first2 = Rudolph|last2 = Fittig|year = 1870|url = https://archive.org/stream/zeitschriftfrch22unkngoog#page/n166/mode/1up|title = Ueber das Tetramethylbenzol|trans-title = On tetramethylbenzene|journal = Zeitschrift für Chemie|volume = 6|pages = 161–162}}</ref> It is produced by methylation of other methylated benzene compounds such as ''p''-xylene and pseudocumene.<ref name = OrgSynth>{{OrgSynth|title = Durene|first = Lee Irvin|last = Smith|year = 1930|volume = 10|page = 32|doi = 10.15227/orgsyn.010.0032|collvol = 2|collvolpages = 248|prep = CV2P0248}}</ref> :C<sub>6</sub>H<sub>4</sub>(CH<sub>3</sub>)<sub>2</sub> + 2 CH<sub>3</sub>Cl → C<sub>6</sub>H<sub>2</sub>(CH<sub>3</sub>)<sub>4</sub> + 2 HCl In industry, a mixture of xylenes and trimethylbenzenes is alkylated with methanol. Durene can be separated from its isomers by selective crystallization, exploiting its high melting point.<ref>{{Ullmann|first1 = Karl|last1 = Griesbaum|first2 = Arno|last2 = Behr|first3 = Dieter|last3 = Biedenkapp|first4 = Heinz-Werner|last4 = Voges|first5 = Dorothea|last5 = Garbe|first6 = Christian|last6 = Paetz|first7 = Gerd|last7 = Collin|first8 = Dieter|last8 = Mayer|first9 = Hartmut|last9 = Höke|title = Hydrocarbons|year = 2002|doi = 10.1002/14356007.a13_227}}</ref> The original synthesis of durene involved a similar reaction starting from toluene.<ref>{{cite journal|first1 = E.|last1 = Ador|first2 = A.|last2 = Rilliet|title = Ueber durch Einwirkung von Chlormethyl auf Benzol in Gegenwart von Aluminiumchlorid erhaltene Kohlenwasserstoffe|trans-title = Hydrocarbons obtained by the action of methyl chloride on benzene in the presence of aluminum chloride|journal = Chem. Ber.|year = 1879|volume = 12|pages = 329–332|doi = 10.1002/cber.18790120191|url = https://zenodo.org/record/1425188}}</ref>
Durene is a significant byproduct of the production of gasoline from methanol via the "MTG (Methanol to Gasoline) process".<ref name="gas">{{cite web|url = http://nzic.org.nz/ChemProcesses/energy/7D.pdf|title = The Production of Methanol and Gasoline|last1 = Packer|first1 = John|last2 = Kooy|first2 = P.|last3 = Kirk|first3 = C. M.|last4 = Wrinkles|first4 = Claire|publisher = New Zealand Institute of Chemistry|url-status = live|archive-date = September 28, 2006|archive-url = https://web.archive.org/web/20060928103842/http://nzic.org.nz/ChemProcesses/energy/7D.pdf}}</ref>
==Reactions and uses== It is a relatively easily oxidized benzene derivative, with E<sub>1/2</sub> of 2.03 V vs NHE.<ref>{{cite journal|doi=10.1021/ja00326a014|title=Electron transfer from aromatic hydrocarbons and their pi-complexes with metals. Comparison of the standard oxidation potentials and vertical ionization potentials|journal=Journal of the American Chemical Society|volume=106|issue=14|pages=3968–3976|year=1984|last1=Howell|first1=J. O.|last2=Goncalves|first2=J. M.|last3=Amatore|first3=C.|last4=Klasinc|first4=L.|last5=Wightman|first5=R. M.|last6=Kochi|first6=J. K.}}</ref> Its nucleophilicity is comparable to that of phenol.<ref name=Ullmanns>{{cite encyclopedia|first1 = Karl|last1 = Griesbaum|first2 = Arno|last2 = Behr|first3 = Dieter|last3 = Biedenkapp|first4 = Heinz-Werner|last4 = Voges|first5 = Dorothea|last5 = Garbe|first6 = Christian|last6 = Paetz|first7 = Gerd|last7 = Collin|first8 = Dieter|last8 = Mayer|first9 = Hartmut|last9 = Höke|chapter = Hydrocarbons|encyclopedia = Ullmann's Encyclopedia of Industrial Chemistry|year = 2002|doi = 10.1002/14356007.a13_227|isbn = 3527306730}}</ref> It is readily halogenated on the ring for example. Nitration gives the dinitro derivative, a precursor to duroquinone. In industry, it is the precursor to pyromellitic dianhydride, which is used for manufacturing curing agents, adhesives, coating materials. It is used in the manufacture of some raw materials for engineering plastics (polyimides) and cross-linking agent for alkyd resins.<ref name=Ullmann>{{cite encyclopedia|first = F.|last = Röhrscheid|chapter = Carboxylic Acids, Aromatic|encyclopedia = Ullmann's Encyclopedia of Industrial Chemistry|year = 2012|doi = 10.1002/14356007.a05_249|isbn = 978-3527306732}}</ref> It is also a suitable starting material for the synthesis of hexamethylbenzene.<ref name = OrgSynth/>
With a simple proton NMR spectrum comprising two signals due to the 2 aromatic hydrogens (2H) and four methyl groups (12H), durene is used as an internal standard.<ref>e.g. in {{cite journal | title = Metal carbonyl anions as model metal-centered nucleophiles in aromatic and vinylic substitution reactions | author = Petr K. Sazonov, Vasyli A. Ivushkin, Galina A. Artamkina, and Irina P. Beletskaya | journal = Arkivoc | year = 2003 | volume = 10 | pages = 323–334 | url = http://www.arkat-usa.org/get-file/19535/}}</ref>
==Safety== Durene is not a skin irritant nor a skin sensitizer or eye irritant. Durene is only slightly toxic on an acute toxicologic basis and only poses an acute health hazard when ingested in excessive quantities.<ref> Dennis W. Lynch, Vernon B. Perone, Ronald L. Schuler, William B. Ushry & Trent R. Lewis, Journal Drug and Chemical Toxicology Volume 1, 1978 - Issue 3, Pages 219-230 (2008) </ref>
==References== <references/>
{{Hydrocarbons}} Category:Hydrocarbon solvents Category:Alkylbenzenes Category:C4-Benzenes