反应详情

To a solution of (R)-4-(tert-butoxycarbonyl)morpholine-2-carboxylic acid (1.05 g, 4.54 mmol) in DMF (10 mL) at 0° C. C, was added DIEA (3.9 mL, 22.7 mmol), followed by HBTU (1.89 g, 4.99 mmol) and HOBt (0.67 g, 4.99 mmol). MeONMHMe.HCl (0.48 g, 4.92 mmol) was added and the resulting solution was warmed to rt and stirred until no starting material remained (˜2 h). The mixture was diluted with H2O (10 mL) and extracted with EtOAc (4×10 mL). The combined organic layers were washed with 1 N aq HCl (10 mL), 1 N aq NaOH (3×10 mL), water (2×10 mL) and brine (10 mL), and dried over Na2SO4. The solvent was removed under vacuum to give (R)-tert-butyl 2-(methoxy(methyl)carbamoyl)morpholine-4-carboxylate (1.40 g, quant.), which was used without further purification. 1H NMR (400 MHz, CDCl3): 4.36 (br, 1 H), 4.08 (m, 1 H), 4.00 (d, 1 H), 3.84 (m, 1 H), 3.76 (s, 3 H), 3.58 (m, 1 H), 3.20 (s, 3 H), 3.04 (m, 2 H), 1.44 (s, 9 H); MS m/z 297 (M+Na+).

1. customat 0° C
2. custom(˜2 h)
3. extractionextracted with EtOAc (4×10 mL)
4. washThe combined organic layers were washed with 1 N aq HCl (10 mL), 1 N aq NaOH (3×10 mL), water (2×10 mL) and brine (10 mL)
5. dry with materialdried over Na2SO4
6. customThe solvent was removed under vacuum