反应详情

A solution of 10.36 g (0.0422 mol) of 2,5-dimethyl-9-methoxy -2,3-dihydro-7H-furo[3,2-g][1]benzopyran-7-one in 150 ml of diphenyl ether was treated with 6.0 g of 10% palladium on charcoal. The mixture was heated under reflux for 5.0 hrs, cooled, and filtered over celite. The catalyst was further washed with methanol, and the filtrate was then concentrated to remove the methanol. The residue was diluted with 1.5 1. of pet. ether and stirred overnight. The product was filtered, washed with pet. ether, dried, and passed through a silica column, eluting with ethyl acetate/benzene, 1:4, to yield pure 9-methoxy -2,5-dimethyl-7H-furo[3,2-g][1]benzopyran-7-one, m.p. 154°-155° (ethanol).

1. temperatureThe mixture was heated
2. temperatureunder reflux for 5.0 hrs
3. temperaturecooled
4. filtrationfiltered over celite
5. washThe catalyst was further washed with methanol
6. concentrationthe filtrate was then concentrated
7. customto remove the methanol
8. additionThe residue was diluted with 1.5 1
9. filtrationThe product was filtered
10. washwashed with pet. ether
11. customdried
12. washeluting with ethyl acetate/benzene, 1:4