反应详情

5-Bromo-2-butyl-3H-imidazole-4-carbaldehyde (38 g, 160 mmol) was dissolved in DMF (400 mL, 5 mol). Potassium carbonate (27 g, 200 mmol) was added followed by methyl 4-bromomethylbenzoate (38 g, 160 mmol) and the solution was stirred at room temperature overnight. The mixture was then concentrated and purified by silica gel chromatography (0-50% EtOAc:hexanes) to yield intermediate (9a) (32.2 g, 62.2 mmol). MS m/z: [M+H+] calcd for C17H19N2O3Br, 379.3. found 379.1. 1H-NMR (400 Mz, CD3OD) δ (ppm): 0.82 (t, 3H, J=5 Hz), 1.28 (m, 2H), 1.54 (q, 2H, J=5 Hz), 2.70 (t, 2H, J=5 Hz), 5.69 (s, 2H), 7.15 (d, 2H, J=5 Hz), 7.96 (d, 2H, J=5 Hz), 9.66 (s, 1H).

1. concentrationThe mixture was then concentrated
2. custompurified by silica gel chromatography (0-50% EtOAc:hexanes)