反应详情

温度

50 °C

216 g of naphthohydroquinone and 527 g of n-octyl alcohol were placed in a 2 l three-necked flask, and 114 ml of concentrated sulfuric acid was dropwisely added thereto for 30 minutes under nitrogen gas stream while stirring. Thereafter, the reaction mixture was heated at 50° C. for 1 hour and then cooled to room temperature. The reaction mixture was extracted with ethyl acetate. The ethyl acetate layer was washed with ammonia-water until the washing reached pH of 5 to 6. The ethyl acetate layer was further washed two times with an aqueous sodium chloride solution and, then, dried with anhydrous sodium sulfate. The dried ethyl acetate solution was concentrated under reduced pressure to precipitate crystals. The crystals were filtered off, and the filtrate was further concentrated under reduced pressure to distill off ethyl acetate and n-octyl alcohol to obtain oily substance. The oily substance was purified by column chromatography using a mixed solvent of n-hexane and ethyl acetate and, then, recrystallized from n-hexane to obtain 190 g of white crystals having a melting point of 73° to 74° C.

1. temperaturecooled to room temperature
2. extractionThe reaction mixture was extracted with ethyl acetate
3. washThe ethyl acetate layer was washed with ammonia-water until the washing
4. washThe ethyl acetate layer was further washed two times with an aqueous sodium chloride solution
5. dry with materialdried with anhydrous sodium sulfate
6. concentrationThe dried ethyl acetate solution was concentrated under reduced pressure
7. customto precipitate crystals
8. filtrationThe crystals were filtered off
9. concentrationthe filtrate was further concentrated under reduced pressure
10. distillationto distill off ethyl acetate and n-octyl alcohol
11. customto obtain oily substance
12. customThe oily substance was purified by column chromatography
13. customrecrystallized from n-hexane