Durene

"Durene, or 1,2,4,5-tetramethylbenzene, is an organic compound with the formula C₆H₂(CH₃)₄. It is a colourless solid with a sweet odor. The compound is classified as an aromatic hydrocarbon. It is one of three isomers of tetramethylbenzene, the other two being prehnitene (1,2,3,4-tetramethylbenzene, m.p. -6.2 °C) and isodurene (1,2,3,5-tetramethylbenzene, m.p. -23.7 °C). Durene has a unusually high melting point, reflecting its high molecular symmetry."

"Durene is an electron-rich arene, exhibiting nucleophilicity comparable to that of phenol.^[1] 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 and coating materials. It is used in the manufacture of some raw materials for engineering plastics (polyimides) and cross-linking agent for alkyd resins."

"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 aninternal standard."