反应详情

A yellow suspension of 7-hydroxyflavone (25.66 g, 0.108 mol), 5-bromo-1-pentene (17.88 g, 14.2 ml, 0.12 mol), and anhydrous, powdered potassium carbonate (30.40 g, 0.22 mol) in acetone (500 ml) was stirred and heated at reflux for 24 hours. The tlc (thin layer chromatography), on silica gel eluted with 20% of hexane in ether, indicated that the reaction was incomplete. Additional 1.5 ml of 5-bromo-1-pentene was added and refluxing was continued for 6 hours and cooled. The solid was filtered and the filtrate was evaporated under vacuum to give a yellow solid 32.63 g, 97% yield. Recrystallization from isopropyl alcohol gave white crystals, mp 104.5°-106° C.; 55% yield (pure).

1. temperatureheated
2. temperatureat reflux for 24 hours
3. washThe tlc (thin layer chromatography), on silica gel eluted with 20% of hexane in ether
4. additionAdditional 1.5 ml of 5-bromo-1-pentene was added
5. temperaturerefluxing
6. temperaturecooled
7. filtrationThe solid was filtered
8. customthe filtrate was evaporated under vacuum