反应详情

4-bromomethyl-2,3-difluorobenzoic acid methyl ester (3.5 g, 13.2 mmol), 5-bromo-2-butyl-3H-imidazole-4-carbaldehyde (3.1 g, 13.2 mmol) and potassium carbonate (1.8 g, 13.2 mmol) were combined and dissolved in DMF (20 mL, 300 mmol). The mixture was stirred at room temperature overnight. The mixture was then diluted with water and extracted with EtOAc. The organic layer was washed with saturated aqueous NaCl, dried over MgSO4, filtered, and concentrated. The crude reaction was purified by silica gel chromatography (0-50% EtOAc:hexanes) to obtain 4.16 g of intermediate (8a) as a yellow solid. MS m/z: [M+H+] calcd for C17H7BrF2N2O3, 416.23; found 417.1. 1H-NMR (CDCl3): 9.68 (1H, s), 7.64 (1H, t), 6.55 (1H, t), 5.64 (2H, s), 3.95 (3H, s), 2.63 (2H, t), 1.69 (2H, m), 1.36 (2H, m) 0.90 (3H, t).

1. extractionextracted with EtOAc
2. washThe organic layer was washed with saturated aqueous NaCl
3. dry with materialdried over MgSO4
4. filtrationfiltered
5. concentrationconcentrated
6. customThe crude reaction
7. customwas purified by silica gel chromatography (0-50% EtOAc:hexanes)