反应详情

((R)-2-Carbamoyl-propyl)-carbamic acid tert-butyl ester (50 mg, 0.247 mmol) was dissolved in THF (1.4 ml). Pyridine (40 ul, 0.49 mmol) and then trifluoroacetic anhydride (42 ul, 0.30 mmol) were added dropwise. The reaction was stirred at room temperature for 1 h and then additional pyridine (40 ul, 0.49 mmol) and trifluoroacetic anhydride (42 ul, 0.30 mmol) were added. The reaction was stirred at room temperature for 16 h then water, sodium carbonate solution and ethyl acetate were added. The aqueous layer was extracted three times with ethyl acetate. The combined organic layers were washed with water and sodium chloride solution, and dried over sodium sulfate. After evaporation, the residue was purified by silica gel chromatography (methanol/dichloromethane) to give 40 mg (87%) of ((R)-2-cyano-2-methyl-ethyl)-carbamic acid tert-butyl ester. (M+Na)+=207.

1. stirringThe reaction was stirred at room temperature for 16 h
2. extractionThe aqueous layer was extracted three times with ethyl acetate
3. washThe combined organic layers were washed with water and sodium chloride solution
4. dry with materialdried over sodium sulfate
5. customAfter evaporation
6. customthe residue was purified by silica gel chromatography (methanol/dichloromethane)