反应详情

3.0 g of 3-hydroxyiminomethyl-7-methylsulfonylamino-6-phenoxy-4H-1-benzopyran-4-one was suspended in 30 ml of acetic acid. Thereto was added 900 mg of sodium acetate. The mixture was refluxed for 3 hours. After the completion of the reaction, the solvent was removed by distillation under reduced pressure. The residue was mixed with 50 ml of ethyl acetate and 50 ml of water. The organic layer was separated, washed with water and a saturated aqueous sodium chloride solution in this order, and dried with anhydrous magnesium sulfate. The solvent was removed by distillation under reduced pressure. The resulting crystal was recrystallized from a mixed solvent of ethyl acetate and ethanol to obtain 2.4 g (yield: 83.9%) of 3-cyano-7-methylsulfonylamino-6-phenoxy-4H-1-benzopyran-4-one having a melting point of 219.5°-220.5° C.

1. temperatureThe mixture was refluxed for 3 hours
2. customAfter the completion of the reaction
3. customthe solvent was removed by distillation under reduced pressure
4. additionThe residue was mixed with 50 ml of ethyl acetate and 50 ml of water
5. customThe organic layer was separated
6. washwashed with water
7. dry with materiala saturated aqueous sodium chloride solution in this order, and dried with anhydrous magnesium sulfate
8. customThe solvent was removed by distillation under reduced pressure
9. customThe resulting crystal was recrystallized from a mixed solvent of ethyl acetate and ethanol