[Br:1][C:2]1[N:3]([CH2:10][O:11][CH2:12][CH2:13][Si:14]([CH3:17])([CH3:16])[CH3:15])[CH:4]=[C:5]([C:7]([OH:9])=O)[N:6]=1.CN(C(ON1N=NC2C=CC=NC1=2)=[N+](C)C)C.F[P-](F)(F)(F)(F)F.[CH2:42]([NH:46][CH2:47][CH2:48][CH2:49][CH3:50])[CH2:43][CH2:44][CH3:45].C(N(C(C)C)CC)(C)C>CN(C=O)C>[Br:1][C:2]1[N:3]([CH2:10][O:11][CH2:12][CH2:13][Si:14]([CH3:17])([CH3:16])[CH3:15])[CH:4]=[C:5]([C:7]([N:46]([CH2:47][CH2:48][CH2:49][CH3:50])[CH2:42][CH2:43][CH2:44][CH3:45])=[O:9])[N:6]=1To a stirred solution of 2-bromo-1-((2-(trimethylsilyl)ethoxy)methyl)-1H-imidazole-4-carboxylic acid (2.4 g, 7.47 mmol) in dry DMF (40 mL) was added HATU (4.26 g, 11.2 mmol), dibutylamine (1.15 g, 8.9 mmol) and diisopropyl ethylamine (2.84 g, 22.4 mmol) successively at 0° C. The reaction mixture was allowed to warm to room temperature over 30 minutes and stirring was continued for 16 h. The reaction mixture was concentrated in vacuo, diluted with EtOAc and washed with water. The organic layer was dried over Na2SO4 and concentrated in vacuo to give crude compound. The crude material was purified by flash chromatography (gradient from 20 to 30% EtOAc/hexanes) to provide the title compound (2.81 g, 87%). 1H NMR (CDCl3) δ 7.68 (s, 1H), 5.28 (s, 2H), 3.89 (t, J=8.0 Hz, 2H), 3.56 (t, J=8.0 Hz, 2H), 3.44 (t, J=8.0 Hz, 2H), 1.57-1.65 (m, 4H), 1.25-1.45 (m, 4H), 0.91-0.95 (m, 8H), 0.01 (s, 9H); MS(ESI+) m/z 434.2 (M+H)+.
Loading…