反应详情

Step L (1): tert-Butyl 3-(hydroxymethyl)morpholine-4-carboxylate. To a solution of 4-(tert-butoxycarbonyl)morpholine-3-carboxylic acid (4.7 g, 20.35 mmol) in THF (120 mL) were added Hunig's base (6.6 g, 50.875 mmol). Then chloroethylformate (2.65 g, 24.4 mmol) was added at 0° C. After stirring from 0° C. to rt over 1.5 h, NaBH4 (3.1 g, 81.4 mmol) was added and after 15 min, MeOH (20 mL) was added slowly at 0° C. After stirring at rt for 1 h, THF and MeOH was removed and ethyl acetate (600 mL) was added and the mixture was washed with NaHCO3, H2O, and dried (Na2SO4), and concentrated in vacuo. 3.56 g of product was obtained as the title compound (81% yield): 1H NMR (CDCl3, 500 MHz) δ 1.46 (9H, s), 2.03 (1H, brd s), 3.17 (1H, m), 3.46 (1H, m), 3.56 (1H, m), 3.72-3.86 (4H, m), 3.91 (1H, d, J=10 Hz), 3.99 (1H, brd s).

1. stirringAfter stirring at rt for 1 h
2. customTHF and MeOH was removed
3. additionethyl acetate (600 mL) was added
4. washthe mixture was washed with NaHCO3, H2O
5. dry with materialdried (Na2SO4)
6. concentrationconcentrated in vacuo