反应详情

温度

-70 °C

2.5M n-butyllithium in hexanes (20.0 cm3, 0.05 mol) was added dropwise to a solution of 2,7-dibromo-9,9-dioctylfluorene (20.0 g, 0.0364 mol) and tetrahydrofuran (300 cm3) maintaining a temperature of −70° C. After stirring for 1 h, trimethylborate (9.45 g, 0.09 mol) was added dropwise. After allowing the solution to reach RT, 20% hydrochloric acid (100 cm3) was added and the solution stirred for a further 1.5 h. The product was extracted into diethyl ether (2×100 cm3) and the combined extracts washed with water (2×100 cm3), dried (MgSO4) and concentrated to a pale yellow oil. Diethyl ether (200 cm3) and hydrogen peroxide (30%, 100 cm3) were added and the solution heated under gentle reflux for 2.5 h with vigorous stirring. The ether layer was separated off and the aqueous layer extracted into diethyl ether (3×50 cm3). The combined organic layers were washed with saturated sodium metabisulphite solution (2×100 cm3), dried (MgSO4), filtered and evaporated down under slightly reduced pressure to a pale yellow oil, which was purified by column chromatography [silica gel, dichloromethane:hexane:ethanol 50:50:1] and recrystallisation from hexane to yield a white crystalline solid (yield 7.80 g, 45%), GC: 99%, mpt 110° C.

1. customto reach RT
2. stirringthe solution stirred for a further 1.5 h
3. extractionThe product was extracted into diethyl ether (2×100 cm3)
4. washthe combined extracts washed with water (2×100 cm3)
5. dry with materialdried (MgSO4)
6. concentrationconcentrated to a pale yellow oil
7. additionDiethyl ether (200 cm3) and hydrogen peroxide (30%, 100 cm3) were added
8. temperaturethe solution heated
9. temperatureunder gentle reflux for 2.5 h with vigorous stirring
10. customThe ether layer was separated off
11. extractionthe aqueous layer extracted into diethyl ether (3×50 cm3)
12. washThe combined organic layers were washed with saturated sodium metabisulphite solution (2×100 cm3)
13. dry with materialdried (MgSO4)
14. filtrationfiltered
15. customevaporated down under slightly reduced pressure to a pale yellow oil, which
16. customwas purified by column chromatography [silica gel, dichloromethane:hexane:ethanol 50:50:1] and recrystallisation from hexane