反应详情

To a chilled (−78° C.) solution of 3-bromo-isoxazole-5-carboxylic acid methoxy-methyl-amide (1.20 g, 5.11 mmol) in THF (56 mL) was added a 1 M solution of ethylmagnesium bromide (13.0 mL, 13.0 mmol) in THF dropwise over a 5 minutes period. The reaction was monitored by TLC (hexanes-EtOAc 4:1). After 5 hours, the reaction was transferred via a 16 gauge cannula to a 0° C. solution of saturated aqueous NH4Cl (75 mL). The resultant heterogeneous mixture was warmed to room temperature and maintained at this temperature for 15 hours. The aqueous phase was then extracted with Et2O (2×) and EtOAc (2×). The combined organic extracts were washed with brine, dried over Na2SO4, filtered and concentrated in vacuo to afford 1-(3-bromo-isoxazol-5-yl)-propan-1-one as an orange solid which was used without further purification.

1. customwas transferred via a 16 gauge cannula to a 0° C.
2. temperaturemaintained at this temperature for 15 hours
3. extractionThe aqueous phase was then extracted with Et2O (2×) and EtOAc (2×)
4. washThe combined organic extracts were washed with brine
5. dry with materialdried over Na2SO4
6. filtrationfiltered
7. concentrationconcentrated in vacuo