反应详情

2-Butyl-3H-imidazole-4-carbaldehyde (30.0 g, 197 mmol) was dissolved in DMF (220 mL, 2.8 mol). NBS (36.8 g, 207 mmol) was added and the mixture was stirred at room temperature overnight. The mixture was then concentrated and taken up in EtOAc and water. The aqueous layer was extracted three times with EtOAc, and the combined organic extracts washed with saturated aqueous NaCl, dried over MgSO4, filtered, and concentrated. The mixture was purified by silica gel chromatography (0-50% EtOAc:hexanes) to obtain 7.8 g of the title compound as a gray solid. MS m/z: [M+H+] calcd for C8H11BrN2O, 232.09. found 233.0. 1H-NMR (DMSO): 13.3 (1H, br), 9.48 (1H, s), 2.66 (2H, t), 1.59 (2H, m), 1.25 (2H, m), 0.85 (3H, t).

1. concentrationThe mixture was then concentrated
2. extractionThe aqueous layer was extracted three times with EtOAc
3. washthe combined organic extracts washed with saturated aqueous NaCl
4. dry with materialdried over MgSO4
5. filtrationfiltered
6. concentrationconcentrated
7. customThe mixture was purified by silica gel chromatography (0-50% EtOAc:hexanes)