| 摘要 |
PROBLEM TO BE SOLVED: To purify binaphthol in an industrially advantageous and convenient way by removing by-product in oxidation coupling reaction of β-naphthol into an aqueous phase after oxidation reaction of the by-product in an organic solvent in the presence of an alkaline compound. SOLUTION: This method is to add (A) 0.1-0.5 N alkali aqueous solution to a mixed solution between a reaction product obtained by oxidation coupling reaction of β-naphthol and an organic solvent having a permittivity of l to 7 (preferably an aromatic hydrocarbon such as xylene or toluene), followed by agitation while oxidation reaction of the above reaction product, and to leave them to (B) stand, followed by removing an aqueous phase and by crystallizing the objective product from an organic phase. The mixed solution is obtained e.g. by removing a solid catalyst from a solution of the reaction product obtained by oxidation coupling reaction of β-naphthol in an organic solvent having a permittivity of 1 to 7 in the presence of a supported catalyst. The oxidation reaction preferably is carried out by contacting with an oxygen- containing gas. |
