反应详情

Tert-butoxycarbonyl-L-phenylalanine (20.00 g), paraformaldehyde (6.04 g) and pyridinium p-toluenesulfonate (0.95 g) were added to toluene (200 ml), and they were stirred under heating and reflux for 30 minutes. The reaction mixture was cooled to room temperature and washed with a saturated aqueous sodium hydrogencarbonate solution and saturated aqueous sodium chloride solution. The obtained toluene layer was dried over anhydrous sodium sulfate and then sodium sulfate was removed. The solvent was evaporated under reduced pressure. The concentrated solution was cooled to room temperature to crystallize the product. The crystals were separated and dried to obtain intended (4S)-N-tert-butoxycarbonyl-4-phenylmethyloxazolidin-5-one (15.10 g) (yield: 72%). 1H-NMR(CDCl3, 300 MHz) δ ppm: 1.51 (9H, s), 3.15 (d, 1H), 3.20-3.52 (m, 1H), 4.13-4.38 (m, 1H), 4.49 (bs, 1H), 5.06-5.38 (m, 1H), 7.12-7.22 (m, 2H), 7.22-7.35 (m, 3H)

1. temperatureunder heating
2. temperaturereflux for 30 minutes
3. washwashed with a saturated aqueous sodium hydrogencarbonate solution and saturated aqueous sodium chloride solution
4. dry with materialThe obtained toluene layer was dried over anhydrous sodium sulfate
5. customsodium sulfate was removed
6. customThe solvent was evaporated under reduced pressure
7. temperatureThe concentrated solution was cooled to room temperature
8. customto crystallize the product
9. customThe crystals were separated
10. customdried