反应详情

温度

-78 °C

To an oven dried roundbottom flask is added 1-(benzofuran-5-yl)propan-1-one (160 mg, 0.919 mmol) and dissolved in dry THF (5 ml). The flask is then cycled through a vacuum/N2 protocol and then cooled under N2 to −78° C. using dry ice/acetone. At this temperature, lithium bis(trimethylsilyl)amide (1M in hexanes) (1.378 ml, 1.378 mmol) is added and stirring continues for ˜30 mins. After this time, NBS (180 mg, 1.010 mmol) in THF (5 ml) is then added dropwise keeping the temp below −60° C. The mixture is left to warm to RT and stirring continued for ˜5 hr. After this time, LCMS looked to show ˜50% conversion to product. The raection is quenched by addition of NH4Cl and allowed to warm to RT. The contents are transferred to a separating funnel and extracted into EtOAc. The organic portion is washed with NaHCO3, water, brine, dried (MgSO4) and evaporated to give a clear oil. Purification by chromatography on silica gel (20 g) eluting with 100% iso-hexane followed by 5% EtOAc/iHex affords the title product as a clear oil. MS: m/z 253 [M+H]+.

1. customTo an oven dried roundbottom flask
2. customthe temp below −60° C
3. waitThe mixture is left
4. temperatureto warm to RT
5. stirringstirring
6. waitcontinued for ˜5 hr
7. customThe raection is quenched by addition of NH4Cl
8. temperatureto warm to RT
9. customThe contents are transferred to a separating funnel
10. extractionextracted into EtOAc
11. washThe organic portion is washed with NaHCO3, water, brine
12. dry with materialdried (MgSO4)
13. customevaporated
14. customto give a clear oil
15. customPurification by chromatography on silica gel (20 g)
16. washeluting with 100% iso-hexane