反应详情

A stirred solution of 5.40 g (14.1 mmol) (4R,9aR)-7-bromo-4,6-dimethyl-3,4,9,9a-tetrahydro-1H-2,4a,5-triaza-fluorene-2-carboxylic acid tert-butyl ester in 350 mL diethyl ether was cooled to −100 deg C. and 6.30 mL (5.13 g, 27.7 mmol) triisopropyl borate was added. To this solution, 11.3 mL (16.9 mmol) tert-butyllithium (1.5 M in n-pentane) was added dropwise and the reaction was stirred at this temperature for another 15 min. The reaction was warmed to −75 deg C., stirred for another 15 min., warmed to 0 deg C., stirred again for 15 min. and then 6.85 mL acetic acid (50% in water) and 0.12 g 35% hydrogen peroxide solution were added successively. The cooling bath was removed and the reaction was stirred for 1 h at room temperature. The reaction mixture was extracted with 10% aqueous thiosulfate solution, the organic layer was washed with brine, dried over magnesium sulfate and filtered. The solvent was removed at a rotary evaporator and the residue was purified by column chromatography on silica gel (0.032–0.063 mm) with ethyl acetate:n-hexane (1:1) as eluant to give the compound as a light yellow solid (75.4%).

1. temperatureThe reaction was warmed to −75 deg C
2. stirring, stirred for another 15 min.
3. temperaturewarmed to 0 deg C
4. stirring, stirred again for 15 min.
5. customThe cooling bath was removed
6. stirringthe reaction was stirred for 1 h at room temperature
7. extractionThe reaction mixture was extracted with 10% aqueous thiosulfate solution
8. washthe organic layer was washed with brine
9. dry with materialdried over magnesium sulfate
10. filtrationfiltered
11. customThe solvent was removed at a rotary evaporator
12. customthe residue was purified by column chromatography on silica gel (0.032–0.063 mm) with ethyl acetate:n-hexane (1:1) as eluant