反应详情

To a solution of 116 g (0.55 mol) of 25 in 200 mL of dry dichloromethane, 1.5 g of iron turnings was added, and then a solution of 41.4 mL (136 g, 0.83 mol) of bromine in 500 mL of dichloromethane was added dropwise with vigorous stirring for 20 min. This mixture was refluxed for 30 min, and then 1200 mL of water was added. The organic layer was separated, and the aqueous layer was extracted with 2×300 mL of dichloromethane. The combined organic extract was washed by saturated aqueous Na2SO3, dried over K2CO3, and then evaporated to dryness. Drying the residue in vacuum gave 138 g (86%) of the title product (bp 165-172° C./1 mm).

1. temperatureThis mixture was refluxed for 30 min
2. customThe organic layer was separated
3. extractionthe aqueous layer was extracted with 2×300 mL of dichloromethane
4. extractionThe combined organic extract
5. washwas washed by saturated aqueous Na2SO3
6. dry with materialdried over K2CO3
7. customevaporated to dryness
8. customDrying the residue in vacuum