反应详情

To a solution of chlorosulfonyl isocyanate (0.15 mL, 1.75 mmol) in 4 mL of CH2Cl2, cooled in a ice bath, is added t-butanol (0.17 mL, 1.75 mmol). The mixture is warmed to ambient temperature and stirred for 15 min. The solution is cooled in an ice bath and a solution of (7-benzyloxy-3-methoxy-2-oxo-2H-chromen-6-ylamino)-acetic acid methyl ester (0.430 g, 1.17 mmol) and triethylamine (0.35 mL, 2 mmol) is added dropwise. After addition is complete, the mixture is warmed to ambient temperature and stirred for 1.5 h. To this is added water (1 mL) and the mixture is extracted with EtOAc. The organic layer is washed with water, sat. NaCl and dried over sodium sulfate. The solvent is removed under reduced pressure to afford N-(t-butoxycarbonylsulfamoyl)-N-(7-benzyloxy-3-methoxy-2-oxo-2H-chromen-6-yl)glycine methyl ester as a white solid: 1H NMR (CDCl3) δ 7.78 (s, 1H), 7.71 (s, 1H), 7.38-7.30 (m, 5H), 6.82, (s, 1H), 6.78 (s, 1H), 5.18 (s, 2H), 4.55 (s, 2H), 3.83 (s, 3H); 3.66 (s, 3H), 1.41 (s, 9H); (M+H)+=549.

1. temperatureThe solution is cooled in an ice bath
2. additionAfter addition
3. temperaturethe mixture is warmed to ambient temperature
4. stirringstirred for 1.5 h
5. extractionthe mixture is extracted with EtOAc
6. washThe organic layer is washed with water, sat. NaCl
7. dry with materialdried over sodium sulfate
8. customThe solvent is removed under reduced pressure