Process for producing 4-hydroxydiphenyl ether

[0050] Example 1

[0051] 1) Put 0.17g (1.0mmol) of diphenyl ether, 0.5mL of o-dichlorobenzene and 0.16g (1.2mmol) of aluminum chloride into a nitrogen-substituted 50mL eggplant flask, and add 0.09g of it while stirring at 50°C (1.1 mmol) Acetyl chloride. After stirring at the same temperature for 3 hours to react, it was cooled to room temperature, 10 mL of water was added, and extracted with 20 mL of diethyl ether. After drying the organic layer with sodium sulfate, the sodium sulfate was filtered off, and the obtained organic layer was concentrated to obtain an oily substance containing 4-acetyldiphenyl ether. This oil was purified by thin-layer chromatography (developing solution: hexane/ethyl acetate) to obtain 0.21 g of 4-acetyldiphenyl ether. Yield: 98%.

[0052] 2) Put 0.17g (1.0mmol) of diphenyl ether, 2mL of 1,2-dichloroethane and 0.27g (2mmol) of aluminum chloride into a nitrogen-substituted 50mL eggplant flask, and stir at 80°C 0.12 g (1.2 mmol) of acetic anhydride was added. After stirring at the same temperature for 3 hours to react, it was cooled to room temperature, 10 mL of water was added, and extracted with 20 mL of tert-butyl methyl ether. After drying the organic layer with sodium sulfate, the sodium sulfate was filtered off, and the obtained organic layer was concentrated to obtain an oily substance containing 4-acetyldiphenyl ether. The oil was quantified by high-performance liquid chromatography (hereinafter abbreviated as LC), and the yield of 4-acetyldiphenyl ether was 85%.

[0053] 3) Put 8.51g (50mmol) of diphenyl ether, 20mL of 1,2-dichloroethane and 8.0g (60mmol) of aluminum chloride into a nitrogen-substituted 100mL eggplant flask, and add them while stirring at 40°C. 4.32 g (55 mmol) of acetyl chloride. After stirring at the same temperature for 3 hours to make it react, it was cooled to room temperature, 100 mL of water was slowly added, and it was extracted with 100 mL of toluene. The organic layer was washed twice with water, each time with 100 mL of water, dried over sodium sulfate, sodium sulfate was filtered off, and the obtained organic layer was concentrated to obtain an oily substance containing 4-acetyldiphenyl ether. The oil was purified by column chromatography to obtain 9.3 g of 4-acetyldiphenyl ether. Yield: 88%.

[0054] 4) In the above 2), except that 2 mL of chlorobenzene was used instead of 1,2-dichloroethane, the same operation as 2) was performed to obtain 4-acetyl diphenyl ether in a yield of 74% (quantified by LC).

[0055] 5) In the above 2), except that 0.19g (1.2mmol) ferric chloride is used instead of aluminum chloride and the reaction temperature is not 80°C but 50°C, the same operation as 2) is carried out to obtain 4- Acetyl diphenyl ether (quantified by LC).

[0056] 6) 0.21 g (1.0 mmol) of 4-acetyl diphenyl ether obtained in 3) was dissolved in 2.5 mL of chloroform, 0.26 g (1.5 mmol) of m-chloroperbenzoic acid was added, and stirred at 80° C. for 9 hours. After cooling the reaction solution, 10 mL of saturated aqueous sodium bicarbonate solution was added, extracted with 20 mL of tert-butyl methyl ether, and the organic layer was concentrated. The resulting concentrate was dissolved in 2.5 mL of methanol, 2 drops of concentrated hydrochloric acid were added, and stirred at 80° C. for 4 hours. The reaction liquid was quantified by LC, and the yield of 4-hydroxydiphenyl ether was 75%.

[0057] Example 2

[0058] Add 4mL of acetic acid and 0.1mL of sulfuric acid into 0.21g (1.0mmol) of 4-acetyl diphenyl ether obtained in 3) of Example 1, then add 0.25g (2.2mmol) of 30% aqueous hydrogen peroxide, and stir at 50°C 8 hours. Quantification of the reaction solution by LC revealed that the yield of 4-hydroxydiphenyl ether was 73%, that is, 4-acetoxydiphenyl ether was contained corresponding to a yield of 11%.