反应详情

To a solution of 1-(tert-butoxycarbonyl)azetidine-3-carboxylic acid (5.15 g, 25.6 mmol) in THF (100 mL) was added DCC (7.11 g, 34.5 mmol), Et3N (5.18 g, 51.2 mmol) and N,O-dimethylhydroxylamine hydrochloride (3.44 g, 35.3 mmol), the reaction was stirred at RT for about 16 hr. Concentrated under reduced pressure to remove solvent, the residue was portioned between EA (100 mL) and water (50 mL), the aqueous was further extracted with EA (50 mL×3). The combined organic phases were washed with brine (20 mL), concentrated under reduced pressure to remove solvent, then purified by column chromatography on silica gel (200-300 mesh, CH2Cl2/MeOH=20/1) to give the crude product (˜8.0 g) as a colorless oil. MS (ESI) m/e [M+23]+ 266.9, [M−55]+ 189.0.

1. concentrationConcentrated under reduced pressure
2. customto remove solvent
3. extractionthe aqueous was further extracted with EA (50 mL×3)
4. washThe combined organic phases were washed with brine (20 mL)
5. concentrationconcentrated under reduced pressure
6. customto remove solvent
7. custompurified by column chromatography on silica gel (200-300 mesh, CH2Cl2/MeOH=20/1)