反应详情

To a solution of the mixture of (R)-N-((R)-2-(6-bromo-3-fluoropyridin-2-yl)-1,1-difluoro-4-hydroxybutan-2-yl)-2-methylpropane-2-sulfinamide and (R)-N-((S)-2-(6-bromo-3-fluoropyridin-2-yl)-1,1-difluoro-4-hydroxybutan-2-yl)-2-methylpropane-2-sulfinamide (0.17 g, 0.422 mmol) in DCM (2.1 ml) was added Dess-Martin periodinane (0.215 g, 0.506 mmol). The reaction mixture was stirred at RT. After 1 h, the mixture was diluted with water and extracted with DCM three times. The organic layer was washed with brine, dried over Na2SO4, and concentrated in vacuo. The crude was purified by silica gel chromatography: 40 g Grace column, 0-50% EtOAc-hexane in 20 min to give a 3:1 mixture of (R)-N-((R)-2-(6-bromo-3-fluoropyridin-2-yl)-1,1-difluoro-4-oxobutan-2-yl)-2-methylpropane-2-sulfinamide and (R)-N-((S)-2-(6-bromo-3-fluoropyridin-2-yl)-1,1-difluoro-4-oxobutan-2-yl)-2-methylpropane-2-sulfinamide (0.12 g, 0.299 mmol, 70.9% yield) was obtained as a colorless oil. MS m/z=401, 403 M+, Calculated for C13H16BrF3N2O2S: 401.24. Used directly in the following step.

1. extractionextracted with DCM three times
2. washThe organic layer was washed with brine
3. dry with materialdried over Na2SO4
4. concentrationconcentrated in vacuo
5. customThe crude was purified by silica gel chromatography
6. custom40 g Grace column, 0-50% EtOAc-hexane in 20 min to give