반응 #159228

반응 방정식

water

MeI

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

NaH

→

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

수율 94.0%

용매

ethyl acetate

THF

반응 조건

후처리

1. 1
   workup.ADDITIONUpon completion of the addition
2. 2
   기타the solution was removed from the ice bath
3. 3
   온도to warm to room temperature
4. 4
   기타the crude reaction mixture
5. 5
   workup.STIRRINGwith stirring
6. 6
   농축The quenched mixture was concentrated in vacuo
7. 7
   기타partitioned between diethyl ether and water
8. 8
   추출The ether layer was extracted with sodium bicarbonate twice
9. 9
   추출extracted three times with ethyl acetate
10. 10
    세척The combined ethyl acetate layers were washed with water, sodium thiosulfate, water
11. 11
    건조dried with sodium sulfate
12. 12
    농축concentrated

실험 절차

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.

출처