反应详情

To a stirred and cooled (0° C.) suspension of (+/−)-3-aminobutanoic acid (5 g; 48.5 mmol) in H2O (30 mL) was added NaOH pellets (3.88 g; 97 mmol) portionwise. The resultant mixture was stirred for 15 min to obtain a clear solution. Benzyl chloroformate (7.1 mL; 50 mmol) as a solution in acetone (30 mL) was added dropwise over 15 min. The reaction was allowed to warm to room temperature and stirred for 3.5 h. The reaction was washed twice with EtOAc (20 mL). The aqueous layer was separated and acidified to pH 2 with 6 N HCl. A precipitate formed and was collected by filtration, washed with H2O and dried in a vacuum oven to afford 3-{[(benzyloxy)carbonyl]amino}-butanoic acid as a white solid. LCMS=238.2 (M+1)+. 1H NMR (CDCl3, 500 MHz): δ 7.34-7.30 (m, 5H), 5.18 (br s, 1H), 5.10 (s, 2H), 4.15-4.10 (m, 1H), 2.59 (s, 2H), 1.27 (d, J=6.9 Hz, 3H).

1. temperaturecooled
2. customto obtain a clear solution
3. stirringstirred for 3.5 h
4. washThe reaction was washed twice with EtOAc (20 mL)
5. customThe aqueous layer was separated
6. customA precipitate formed
7. filtrationwas collected by filtration
8. washwashed with H2O
9. customdried in a vacuum oven