反应详情

To a solution of 4.0 g (32.5 mmol) of 1-(3-pyridyl)ethanol in 25 ml of dichloroethane, 4.96 g (32.6 mmol) of 2,3,5-trimethylhydroquinone and 4.5 ml (50.9 mmol) of trifluoromethanesulfonic acid were added and refluxed by heating for 20 hours in argon atomosphere. After cooling, ice water was added, washed with ethyl acetate to eliminate neutral substances, and made weakly alkaline with a saturated solution of sodium hydrogen carbonate. The resultant substance was extracted with ethyl acetate, and the extract was washed with water, dried, oxidized with air and concentrated under reduced pressure. The residue was purified with silica gel column chromatography (isopropyl ether-ethyl acetate (1:2)), to give 5.1 g of 3,5,6-trimethyl-2-[1-(3-pyridyl)ethyl]-1,4-benzoquinone (yield 61%). Physical data of this compound are shown in Table 1.

1. temperaturerefluxed
2. temperatureby heating for 20 hours in argon atomosphere
3. temperatureAfter cooling
4. washwashed with ethyl acetate
5. extractionThe resultant substance was extracted with ethyl acetate
6. washthe extract was washed with water
7. customdried
8. concentrationconcentrated under reduced pressure
9. customThe residue was purified with silica gel column chromatography (isopropyl ether-ethyl acetate (1:2))