反应详情

温度

0 °C

(2-Amino-ethyl)-(2-benzyloxycarbonylamino-ethyl)-carbamic acid tert-butyl ester was prepared from benzyl 2-aminoethylcarbamate using the same reaction sequence outlined by Andruszkiewicz et al in Synthetic Communications 2008, 38, p. 905-913 (reaction with acrylonitrile, followed by protection of the secondary amine with the BOC group, and conversion of the nitrile group to an amino group with one less methylene unit using the Hoffmann rearrangement). (2-Amino-ethyl)-(2-benzyloxycarbonylamino-ethyl)-carbamic acid tert-butyl ester (500 mg, 1.48 mmol) was taken up in 15 mL of CH2Cl2 along with 4-methylmorpholine (449 mg, 4.44 mmol) and cooled to 0° C. 4-Nitrophenyl chloroformate (328 mg, 1.63 mmol) was then added at 0° C. The resulting reaction mixture was warmed to room temperature and stirred for 16 h. It was then diluted with water. The organic layer was separated, dried (Na2SO4), and concentrated under reduced pressure. Purification by chromatography (95% CH2Cl2, 5% MeOH) afforded the intermediate nitrophenyl carbamate (480 mg; 74%).

1. customThe resulting reaction mixture
2. temperaturewas warmed to room temperature
3. customThe organic layer was separated
4. dry with materialdried (Na2SO4)
5. concentrationconcentrated under reduced pressure
6. customPurification by chromatography (95% CH2Cl2, 5% MeOH)