反应详情

To activated zinc dust (13.3 g, 0.2 mol) in a 1 L flask was added THF (200 mL). Diiodomethane (8.9 mL, 110 mmol) was added dropwise over ˜10 min. The mixture was stirred at room temperature for 30 min. The mixture was cooled with an ice-acetone bath, a solution of tin(iv) chloride 1M in CH2Cl2 (22.1 mL, 22.1 mmol) was added over ˜15 min (needle tip inserted inside the mixture). The mixture was stirred for 15 min and the cooling bath was removed. The mixture was stirred at r.t for 30 min. After cooling back with an ice-acetone bath, a solution of 1-(4-bromophenyl)-2,2-difluoroethanone (5.2 g, 22.12 mmol) in THF (30 mL) was added dropwise over ˜10 min. The cooling bath was removed and the mixture was stirred at room temperature for 30 min. The mixture was then poured portionwise to a mixture of sodium bicarbonate (300 mL, 300 mmol) and hexanes (300 mL) at 0° C. After stirring for 15 min, the mixture was filtered through celite. The organic layer was separated, washed with brine, dried (Na2SO4) and concentrated. Chromatography over silica gel and elution with hexanes: Ethyl acetate (20:1) gave the title compound as a pale yellow liquid.

1. temperatureThe mixture was cooled with an ice-acetone bath
2. stirringThe mixture was stirred for 15 min
3. customthe cooling bath was removed
4. stirringThe mixture was stirred at r.t for 30 min
5. temperatureAfter cooling back with an ice-acetone bath
6. customThe cooling bath was removed
7. stirringthe mixture was stirred at room temperature for 30 min
8. stirringAfter stirring for 15 min
9. filtrationthe mixture was filtered through celite
10. customThe organic layer was separated
11. washwashed with brine
12. dry with materialdried (Na2SO4)
13. concentrationconcentrated
14. washChromatography over silica gel and elution with hexanes: Ethyl acetate (20:1)