تفاعل #159228

معادلة التفاعل

water

MeI

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

NaH

→

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

المردود 94.0%

المذيبات

ethyl acetate

THF

ظروف التفاعل

المعالجة

1. 1
   workup.ADDITIONUpon completion of the addition
2. 2
   أخرىthe solution was removed from the ice bath
3. 3
   درجة الحرارةto warm to room temperature
4. 4
   أخرىthe crude reaction mixture
5. 5
   workup.STIRRINGwith stirring
6. 6
   تركيزThe quenched mixture was concentrated in vacuo
7. 7
   أخرىpartitioned between diethyl ether and water
8. 8
   استخلاصThe ether layer was extracted with sodium bicarbonate twice
9. 9
   استخلاصextracted three times with ethyl acetate
10. 10
    غسيلThe combined ethyl acetate layers were washed with water, sodium thiosulfate, water
11. 11
    تجفيفdried with sodium sulfate
12. 12
    تركيزconcentrated

الإجراء التجريبي

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.

المصدر