反应详情

温度

0 °C

At −5° C. trimethylsilyl trifluoromethanesulfonate (36.9 mmol) is added dropwise to a solution of ethyl acetoacetate (30.7 mmol) and TEA (36.9 mmol) in DCM (50 mL). The solution is stirred for 90 min at 0° C. and treated over 30 min with a solution of bromine (30.7 mmol) in DCM (20 mL). After 60 min water (100 mL) is added, the layers are separated and the aq. layer is extracted three times with water (100 mL each). The organic layer is dried over MgSO4 and concentrated under reduced pressure to give the desired product which is used without further purification. 1H-NMR (CDCl3): δ=1.34 (t, J=7.16 Hz, 3H); 2.46 (s, 3H); 4.31 (q, J=7.20 Hz, 2H); 4.77 (s, 1H).

1. customthe layers are separated
2. extractionthe aq. layer is extracted three times with water (100 mL each)
3. dry with materialThe organic layer is dried over MgSO4
4. concentrationconcentrated under reduced pressure