[O:1]=[C:2]1[CH:6]=[CH:5][C:4](=[O:7])[N:3]1[CH2:8][CH2:9][C:10]([NH:12][CH2:13][CH2:14][CH2:15][CH2:16][CH2:17][CH2:18][CH2:19][C:20]([OH:22])=[O:21])=[O:11].[B-](F)(F)(F)F.CN(C(O[N:36]1[C:41](=[O:42])[CH2:40][CH2:39][C:37]1=[O:38])=[N+](C)C)C.CCN(C(C)C)C(C)C>C1COCC1>[O:38]=[C:37]1[CH2:39][CH2:40][C:41](=[O:42])[N:36]1[O:21][C:20](=[O:22])[CH2:19][CH2:18][CH2:17][CH2:16][CH2:15][CH2:14][CH2:13][NH:12][C:10](=[O:11])[CH2:9][CH2:8][N:3]1[C:4](=[O:7])[CH:5]=[CH:6][C:2]1=[O:1]To a solution of 8-[3-(2,5-dioxo-2,5-dihydropyrrol-1-yl)propionylamino]octanoic acid (917 mg, crude) in dry THF (15 ml) was added TSTU (1.07 mg) and DIPEA (0.65 ml). The mixture was stirred under nitrogen over night. The mixture was concentrated. To the residue was added EtOAc and the precipitate was filtered off. The filtrate was extracted with 0.1 N HCl (2×) and brine (1×), dried (Na2SO4) and concentrated to give an off-white solid. Overall yield 37% (444 mg). LC-MS, M/z: 408.39 (M+1).
読み込み中…