反应详情

32.0 ml (620.0 mmol) of bromine are added dropwise at 0° C. to 63.7 g (563.2 mmol) of 3-fluoro-2-hydroxypyridine in 700 ml of dimethylformamide. After the mixture has been stirred at room temperature for a further two hours, 800 ml of water are added, and 78 g of Na2SO3 in 350 ml of water are added dropwise. The mixture is then extracted three times with 400 ml of dichloromethane in each case, and the organic phase is dried over Na2SO4 and evaporated to dryness, giving 97.6 g of 5-bromo-3-fluoro-2-hydroxypyridine. ##STR21##

1. extractionThe mixture is then extracted three times with 400 ml of dichloromethane in each case
2. dry with materialthe organic phase is dried over Na2SO4
3. customevaporated to dryness