PURPOSE: To purify naphthoquinone useful as an intermediate for dye, and an auxiliary for pulp digesting by a simple operation inexpensively in high purity, by treating crude naphthoquinone with a solid base of a non-alkali metallic compound in an organic solvent.
CONSTITUTION: Crude naphthoquinone which is obtained by washing naphthoquinone with water and collecting it from a formed gas preferably produced by catalytic gaseous-phase oxidation reaction of naphthalene is treated with a solid base of a non-alkali metallic compound, preferably an alkaline earth metal hydroxide, basic alumina or activated clay treated with a base, especially slaked lime in an organic solvent selected from lower hydrocarbons having preferably 80W145°C boiling points, usually xylenes such as ortho-xylene, etc., so naphthoquinone is purified industrially advantageously in the following way wherein a large amount of waste water is not discharged, waste is easily burned, the above-mentioned base is filtered well and there is no reduction in yield.
KOMATSU TATSUMI
SUMINO TOSHIHIKO
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