反应详情

温度

80 °C

To a room temperature solution of 1-bromo-4-(bromomethyl)-2-fluorobenzene from Step 1 (11.8 g) in DMF (150 mL) was added sodium acetate (10.8 g). The mixture was heated at 80° C. for 16 hours. It was cooled to room temperature and poured into ice and saturated aqueous sodium bicarbonate (200 mL), and extracted with diethyl ether (2×100 mL). The combined extracts were washed with brine, dried with magnesium sulfate and the solvent removed in vacuo. The crude material was purified by chromatography on SiO2 using ethyl acetate and hexanes (1:25 to 1:10) to yield 4-bromo-3-fluorobenzyl acetate (containing about 15% of 4-bromo-3-fluorobenzaldehyde). The residue was dissolved in methanol (100 mL), cooled at 0° C. and sodium methoxide (250 mg) was added. The reaction mixture was stirred at room temperature for 2 hours. It was cooled to 0° C. and sodium borohydride was added (1.5 g). Stirred at 0° C. for 1 hour and poured into ice and saturated aqueous ammonium chloride (200 mL). Extracted with ethyl acetate (2×100 mL). The combined extracts were washed with brine, dried with magnesium sulfate and the solvent removed in vacuo. The residue was purified by chromatography on SiO2 using ethyl acetate and hexanes (1:5 to 1:3) to yield the title compound.

1. temperatureIt was cooled to room temperature
2. extractionextracted with diethyl ether (2×100 mL)
3. washThe combined extracts were washed with brine
4. dry with materialdried with magnesium sulfate
5. customthe solvent removed in vacuo
6. customThe crude material was purified by chromatography on SiO2