反应详情

To a solution of 2.03 g (5.29 mmol) of the product of Step B dissolved in 10 mL of carbon tetrachloride was added 0.50 mL (5.29 mmol) of phosphorous tribromide and the reaction mixture was magnetically stirred at room temperature for 1 hour as hydrogen bromide was evolved. The magnetic stir bar was removed, and the reaction mixture was concentrated in vacuo. The residue was redissolved and evaporated from methylene chloride three times to remove most of the hydrogen bromide. Finally, the residue was purified by rapid flash chromatography on a silica gel column eluted with 20% EtOAc-hexane. Combination and evaporation of the purified fractions in vacuo afforded 2.27 (96%) of the title compound.

1. customThe magnetic stir bar was removed
2. concentrationthe reaction mixture was concentrated in vacuo
3. dissolutionThe residue was redissolved
4. customevaporated from methylene chloride three times
5. customto remove most of the hydrogen bromide
6. customFinally, the residue was purified by rapid flash chromatography on a silica gel column
7. washeluted with 20% EtOAc-hexane
8. customCombination and evaporation of the purified fractions in vacuo