1911 Encyclopædia Britannica/Durene
DURENE (1·2·4·5 tetramethyl benzene) C6H2(CH3)4, a hydrocarbon which has been recognized as a constituent of coal-tar. It may be prepared by the action of methyl iodide on brompseudocumene or 4·6 dibrom metaxylene, in the presence of sodium; or by the action of methyl chloride on toluene, in the presence of anhydrous aluminium chloride. It crystallizes in plates, having a camphor-like smell, melting at 79-80° C. and boiling at 189-191° C. It is easily soluble in alcohol, ether and benzene, and sublimes slowly at ordinary temperature. On oxidation with chromic acid mixture, it is completely decomposed into carbon dioxide and acetic acid; nitric acid oxidizes it to durylic and cumidic acids [C6H2·(CH3)2·(COOH)2].