反应详情

To a solution of triphenylphosphine (8.03 g, 30.6 mmol) in 100 ml CH2Cl2 at 0° C. was added dropwise bromine (1.45 ml, 28.1 mmol). After 15 minutes at 0° C. a white precipitate formed and a solution of the product of Step 3, above, (5.93 g, 25.5 mmol) in 30 ml CH2Cl2 was added dropwise. After 1 hour the solvent was removed in vacuo and the residue was taken up in ether to precipitate the triphenylphosphine oxide formed in the reaction. After filtration, evaporation and SGC (5% EtOAc-hexanes) the title compound (5 g) was obtained as a colorless oil which crystallized on standing.

1. customAfter 15 minutes at 0° C. a white precipitate formed
2. customAfter 1 hour the solvent was removed in vacuo
3. customto precipitate the triphenylphosphine oxide
4. customformed in the reaction
5. filtrationAfter filtration, evaporation and SGC (5% EtOAc-hexanes) the title compound (5 g)
6. customwas obtained as a colorless oil which
7. customcrystallized