反应详情

To a solution of methyl 4-methyl-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzoate (compound 5.4, 600 mg, 2.17 mmol) in dioxane (20 mL) was added 2-methyl-4-bromo imidazole (419 mg, 2.6 mmol), Pd(dppf)Cl2.CH2Cl2 (180 mg, 0.22 mmol). The mixture was degassed argon and stirred for 10 minutes then aqueous potassium carbonate (1M, 10 mL, 10 mmol) was added and the mixture was stirred at 90° C. for 18 h. After cooling to ambient temperature, the reaction mixture was diluted with EtOAc and filtered through Celite®. The organic phase was washed by brine, dried (MgSO4), filtered, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (0-5% MeOH in EtOAc) to yield the title compound as a foam (324 mg, 65%). m/z (ES+) 231 (M+H)+. 1H NMR (400 MHz, CDCl3) δ 8.30 (br s, 1H), 7.86 (dd, J=7.9, 1.9 Hz, 1H), 7.32 (d, J=7.9 Hz, 1H), 7.08 (s, 1H), 3.92 (s, 3H), 2.53 (s, 3H), 2.51 (s, 3H).

1. customThe mixture was degassed argon
2. stirringthe mixture was stirred at 90° C. for 18 h
3. filtrationfiltered through Celite®
4. washThe organic phase was washed by brine
5. dry with materialdried (MgSO4)
6. filtrationfiltered
7. concentrationconcentrated under reduced pressure
8. customThe residue was purified by silica gel column chromatography (0-5% MeOH in EtOAc)