反应详情

To a solution of 1-(3-phenyl-5-trifluoromethyl-isoxazol-4-yl)-ethanone (2.88 g, 11 mmol) in chloroform (11 mL) and AcOH (0.6 mL) at 48° C. was added a solution of bromine (0.61 mL, 12 mmol) in chloroform (3.5 mL) over 5 min keeping the temperature below 50° C. After addition the reaction mixture was allowed to cool down to room temperature and poured into ice-water (200 mL). The layers were separated and the aqueous layer extracted with dichloromethane. The combined organic layers were then washed with water and brine, dried over sodium sulphate and evaporated. Purification by chromatography (SiO2, heptane:ethyl acetate: 100:0 to 4:1) afforded the title compound (2.2 g, 59%) which was obtained as a light yellow oil. MS: m/e=334.3/336.4 [M+H]+.

1. customthe temperature below 50° C
2. additionAfter addition the reaction mixture
3. customThe layers were separated
4. extractionthe aqueous layer extracted with dichloromethane
5. washThe combined organic layers were then washed with water and brine
6. dry with materialdried over sodium sulphate
7. customevaporated
8. customPurification by chromatography (SiO2, heptane:ethyl acetate: 100:0 to 4:1)