反应详情

温度

0 °C

0.96 g (5.52 mmol) of 3-bromopyridin-2(1H)-one is dissolved in 17 ml of DMSO. The mixture is cooled to 0° C., and 1.00 g (5.52 mmol) of potassium tert-butoxide is added such that the internal temperature does not exceed 30° C. After 1 h at room temperature, a solution of 1.00 g (5.52 mmol) of the compound from Example 43A in 5 ml of DMSO is added. After 3 h at 80° C., 200 ml of water and 50 ml of sodium chloride solution are added and the mixture is extracted three times with ethyl acetate. The combined organic phases are washed with saturated sodium chloride solution and dried over sodium sulphate. The solvent is removed under reduced pressure and the product is purified by chromatography on silica gel (mobile phase: cyclohexane/ethyl acetate=4:1). This gives 935 mg (49% of theory) of the desired compound as an E/Z isomer mixture.

1. customdoes not exceed 30° C
2. waitAfter 3 h at 80° C.
3. extractionthe mixture is extracted three times with ethyl acetate
4. washThe combined organic phases are washed with saturated sodium chloride solution
5. dry with materialdried over sodium sulphate
6. customThe solvent is removed under reduced pressure
7. customthe product is purified by chromatography on silica gel (mobile phase: cyclohexane/ethyl acetate=4:1)