C([O:8][C:9]1[C:14]2[N:15]([CH2:19][CH2:20][O:21][CH3:22])[C:16]([CH3:18])=[N:17][C:13]=2[CH:12]=[C:11]([C:23]([O:25][CH3:26])=[O:24])[CH:10]=1)C1C=CC=CC=1>[Pd].CO>[OH:8][C:9]1[C:14]2[N:15]([CH2:19][CH2:20][O:21][CH3:22])[C:16]([CH3:18])=[N:17][C:13]=2[CH:12]=[C:11]([C:23]([O:25][CH3:26])=[O:24])[CH:10]=1A mixture of methyl 7-(benzyloxy)-1-(2-methoxyethyl)-2-methyl-1H-benzimidazole-5-carboxylate (9.21 g, 26.0 mmol, Step 6) and 10% palladium on carbon (500 mg) in methanol (150 mL) was stirred under hydrogen gas (4 atm) for 5 hours. The resulting mixture was filtered through a pad of Celite, and the filtrate was concentrated in vacuo. The residue was suspended in diisopropyl ether (150 mL), and the precipitate was collected by filtration to afford the title compound as a gray solid (6.35 g, 92%).
Wird geladen…