Cl[C:2]([O:4][CH2:5][C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1)=[O:3].[CH2:12]([NH2:15])[CH2:13][NH2:14].[OH-:16].[Na+]>>[C:2]([N:14]([C:2]([O:4][CH2:5][C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1)=[O:16])[CH2:13][CH2:12][NH2:15])([O:4][CH2:5][C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1)=[O:3]Benzyl chloroformate (40 mL, 280 mmol) was added dropwise over 45 min to a vigorously stirred solution of ethylenediamine (9.4 mL, 0.5 equiv) in 1M NaOH (310 mL, 1 equiv) at 0° C. A heavy white precipitate formed and the mixture was stirred for 4 h following addition. The resulting solid product was collected by filtration, washed with water and then hexane, and then air-dried overnight (46.17 g, 100%). 1H-NMR (CDCl3) δ 3.32 (s, 4H), 5.10 (s, 4H), 5.23 (br, 2H), 7.35 (s, 10HS MS (ESI) 329.3 (MH)+.
Wird geladen…