反应详情

4-[3,5,6-trimethyl-1,4-benzoquinon-2-yl-(3-pyridyl)methyl]-α-methylcinnamic acid, 0.7 g (1.75 mmol), was hydrogenated with 0.2 g of 5% Pd-carbon in 6 ml of acetic acid (the reaction completed in about 2 hours). The catalyst was filtered off, and the filtrate was concentrated, to which water was added and neutralized with a saturated aqueous solution of sodium hydrogen carbonate. The resultant substance was extracted with ethyl acetate, and oxidized by shaking with an aqueous solution of ferric chloride. After the organic phase was washed with water and dried, the solvent was evaporated off and the residue was purified with silica gel column chromatography (ethyl acetate-ethanol (9:1)) and recrystallized from ethyl acetate, to give 0.3 g (44.2%) of 3-(4-[3,5,6-trimethyl-1,4-benzoquinon-2-yl-(3-pyridyl)methyl]phenyl)propionic acid. The physical data are shown in Table 1.

1. filtrationThe catalyst was filtered off
2. concentrationthe filtrate was concentrated, to which water
3. additionwas added
4. extractionThe resultant substance was extracted with ethyl acetate
5. washAfter the organic phase was washed with water
6. customdried
7. customthe solvent was evaporated off
8. customthe residue was purified with silica gel column chromatography (ethyl acetate-ethanol (9:1))
9. customrecrystallized from ethyl acetate