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Methods of synthesis for l-ethyl-3-methylbenzene,of m-xylene the intermediate 1,2,3-trimethylbeiizene, and m-xylene which are applic-3,5-dimethyll-1 -cyclohexanol was prepared b y hydrogenratory to study aromatic able to the production of 10-gallon quantities of pure hyhydrocarbons as possible drocarbon are described. The three compounds were preation of commercial 3,5-dicomponents of aviation g a m pared by the dehydrogenation of suitablecyclohexeneintermethy 1 -1 -hydroxybenzene line, the development of mediates. Physical constants and freezing or melting (3,5-x~lenol, 3,5-dimethylmethods of synthesis readily curves for the three aromatic hydrocarbons are reported.Phenol). adaptable to the preparation In the large scale prepaof 10-gallon quantities of the ration of these compounds pure hydrocarbons was necessary. This paper presents the methseveral runs were made at each stage before the next step was ods developed for the large scale syntheses of 1,2,3-trimethylbegun. For this reason typical quantities of reactants used are benzene (6), 1-ethyl-3-methylbenzene (,$?), and mxylene by the given under experimental details for the stepwise synthesis of dehydrogenation of the corresponding cyclohexene interthe hydrocarbons. mediates.Physical constants of the 1,2,3-trimethylbenzene, l-ethyl-3-1,2,3-Trimethylbenzene was prepared according to a general methylbenzene, and m-xylene are listed in Table I together with method outlined by Tom and Boord (9) in which piperylene selected literature values. The properties were obtained by (l,3-pentadiene) and crotonaldehyde were condensed to the methods previously described ( 3 ) . Freezing curves for 1,2,3-2,6-and 5,6-dimethyl-3-cyclohexene-l-carboxaldehydes, followed trimethylbenzene and mxylene, and a melting curve for 1-by hydrogenation to the 2,3-and 2,6-dimethylcyclohexylcarbinols, dehydration to the 1,2,3-trimethylcyclohexenes, and a program at this labo-
