反应 #159228

反应方程式

water

MeI

2-tert-Butoxycarbonylamino-3-hydroxy-3-methyl-butyric acid

NaH

→

2-tert-Butoxycarbonylamino-3-methoxy-3-methyl-butyric acid

收率 94.0%

溶剂

ethyl acetate

THF

反应条件

后处理

1. 1
   workup.ADDITIONUpon completion of the addition
2. 2
   其他the solution was removed from the ice bath
3. 3
   温度to warm to room temperature
4. 4
   其他the crude reaction mixture
5. 5
   workup.STIRRINGwith stirring
6. 6
   浓缩The quenched mixture was concentrated in vacuo
7. 7
   其他partitioned between diethyl ether and water
8. 8
   萃取The ether layer was extracted with sodium bicarbonate twice
9. 9
   萃取extracted three times with ethyl acetate
10. 10
    洗涤The combined ethyl acetate layers were washed with water, sodium thiosulfate, water
11. 11
    干燥dried with sodium sulfate
12. 12
    浓缩concentrated

实验过程

2-tert-Butoxycarbonylamino-3-hydroxy-3-methyl-butyric acid (1.0 g, 4.29 mmol) was dissolved in THF (14 mL) and cooled to 0° C. in an external ice/brine bath. MeI (2.13 mL, 34.3 mmol) was added at 0° C. Solid NaH (60% dispersion in mineral oil, 0.514 g, 12.87 mmol) was added slowly at 0° C. Upon completion of the addition, the solution was removed from the ice bath and allowed to warm to room temperature, and stirred. After 18 hours, the crude reaction mixture was diluted in ethyl acetate and water was added slowly with stirring. The quenched mixture was concentrated in vacuo and partitioned between diethyl ether and water. The ether layer was extracted with sodium bicarbonate twice. The combined bicarbonate layers were acidified with aqueous citric acid to pH 3 and extracted three times with ethyl acetate. The combined ethyl acetate layers were washed with water, sodium thiosulfate, water, dried with sodium sulfate and concentrated to yield 2-tert-Butoxycarbonylamino-3-methoxy-3-methyl-butyric acid (0.99 g, 94%) as an oil.

来源