反应详情

To a stirred solution of ethyl chloroformate (4 g, 0.037 mol.) and N-hydroxysuccinimide (6.3 g, 0.055 mol.) in 10 mL of DCM at 0° C. under nitrogen atmosphere was added N,N-Diisopropylethylamine (9.5 g, 0.055 mol) in 10 mL of DCM. The progress of the reaction was monitored by thin layer chromatography (TLC). After stirring for 3 hrs at room temperature, the reaction mixture was filtered and the precipitate was washed with 2×10 mL of dichloromethane. The combined filtrate was evaporated and dissolved in 20 mL of acetonitrile, cooled in an ice-bath and then added dropwise a solution of Ethanolamine 23 (3.3 mL, 2.5 eq). The resulting mixture was stirred at ice-bath temperature for 1 h and then overnight at room temperature. The progress of the reaction was monitored by thin layer chromatography (TLC). The reaction mixture was filtered, and the precipitate was washed with 2×10 mL DCM and dried over sodium sulfate. After removing the solvent under reduced pressure, the residue was purified by silica gel column chromatography to give ethyl (2-hydroxyethyl)carbamate.

1. filtrationthe reaction mixture was filtered
2. washthe precipitate was washed with 2×10 mL of dichloromethane
3. customThe combined filtrate was evaporated
4. dissolutiondissolved in 20 mL of acetonitrile
5. temperaturecooled in an ice-bath
6. stirringThe resulting mixture was stirred at ice-bath temperature for 1 h
7. customovernight
8. customat room temperature
9. filtrationThe reaction mixture was filtered
10. washthe precipitate was washed with 2×10 mL DCM
11. dry with materialdried over sodium sulfate
12. customAfter removing the solvent under reduced pressure
13. customthe residue was purified by silica gel column chromatography