| 摘要 |
PURPOSE:To obtain high-purity 2,3-dimethylnaphthalene as an insoluble substance, by bringing crude 2,3-dimethylnaphthalene having other isomers as an impurity into contact with methanol in an amount insufficient to dissolve the whole dimethylnaphthalene. CONSTITUTION:Crude 2,3-dimethylnaphthalene containing other isomers as a main impurity is brought into contact with methanol in an amount insufficient to dissolve the whole dimethylnaphthalene, and high-purity 2,3- dimethylnaphthalene is recovered as an insoluble substance. The concrete amount of methanol used is usually 0.3-2 times as much as the whole amounts of dimethylnaphthalene by weight, and the contact treatment operation is carried out by a method wherein the crude substance is added to methanol at room temperature, suspended while stirring, and extraction is carried out partially, by a so-called suspension and washing method wherein methanol is sprinkled upon the crude substance and liquid separation is carried out by centrifuging, or other methods.
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