反应详情

To a solution of 5-bromo-3-fluoro-2-hydroxybenzaldehyde from step 4A (2.0 g, 9.13 mmol) in DMF (36.5 ml) was added 4-bromo-1-butene (3.71 ml, 36.5 mmol) and potassium carbonate (1.58 g, 11.4 mmol). The resulting mixture was stirred at rt overnight. The reaction mixture was diluted with EtOAc (100 mL), washed with water (3×30 mL) and brine (30 mL), dried over magnesium sulfate, and then filtered and concentrated in vacuo. Purification by silica gel column chromatography (0-20% EtOAc/hexanes) gave 5-bromo-2-(but-3-enyloxy)-3-fluorobenzaldehyde (2.38 g, 8.71 mmol, 95% yield). 1H NMR (500 MHz, DMSO-d6) δ 10.22 (d, J=0.9 Hz, 1H), 7.98 (dd, J=11.3, 2.4 Hz, 1H), 7.63 (dd, J=2.4, 1.2 Hz, 1H), 5.89 (ddt, J=17.1, 10.4, 6.7 Hz, 1H), 5.17 (dd, J=17.2, 1.7 Hz, 1H), 5.12-5.07 (m, 1H), 4.29 (t, J=6.4 Hz, 1H), 2.57-2.49 (m, 3H).

1. washwashed with water (3×30 mL) and brine (30 mL)
2. dry with materialdried over magnesium sulfate
3. filtrationfiltered
4. concentrationconcentrated in vacuo
5. customPurification by silica gel column chromatography (0-20% EtOAc/hexanes)