反应详情

Dimethylsulfoxide (7.16 ml, 100.8 mmol) is added to a solution of oxalyl chloride (4.41 ml, 50.4 mmol) in 126 mL of methylene chloride at −78° C. The mixture is left to stir for fifteen minutes, and a solution of (2RS, 1S)-[1-(2-hydroxy-propylcarbamyl)-ethyl]-carbamic acid tert-butyl ester (9.92 g, 40.32 mmol) in 100 mL of CH2Cl2 is added dropwise. After stirring for 15 minutes at −78° C., the reaction is quenched with triethylamine (28 mL, 381 mmol), and the temperature is allowed to rise to room temperature. The volatile solvents are removed, and the residue is purified by flash column (SiO2, 60% EtOAc/Hexane). The product (1S)-[1-(2-oxo-propylcarbamoyl)-ethyl]-carbamic acid tertbutyl ester (5.93 g, 60%) is isolated as a white solid. MS C11H20N2O4 MS m/z: 245.

1. waitThe mixture is left
2. stirringAfter stirring for 15 minutes at −78° C.
3. customto rise to room temperature
4. customThe volatile solvents are removed
5. customthe residue is purified by flash column (SiO2, 60% EtOAc/Hexane)