反应详情

温度

85 °C

The 4-((2,2-dimethyl-1,3-dioxan-5-yl)methoxy)-2,3-dimethylpyridine 1-oxide (3.84 g, 14.4 mmol) obtained in the step (12a) was mixed with acetic anhydride (50 ml, 530 mmol). The mixture was stirred at 85° C. for 1.5 hours. After cooled to room temperature, the reaction mixture was concentrated. To the residue, methanol (50 ml) and a 5N aqueous sodium hydroxide solution (20 ml, 100 mmol) were added and the mixture was stirred at room temperature for 2.5 hours. The reaction mixture was concentrated and the residue was partitioned between water and ethyl acetate. The organic layer was washed with a 1N aqueous sodium hydroxide solution twice, dried over anhydrous sodium sulfate, filtered and concentrated to obtain the title compound (2.97 g, yield: 77.2%) as a brown solid.

1. temperatureAfter cooled to room temperature
2. concentrationthe reaction mixture was concentrated
3. stirringthe mixture was stirred at room temperature for 2.5 hours
4. concentrationThe reaction mixture was concentrated
5. customthe residue was partitioned between water and ethyl acetate
6. washThe organic layer was washed with a 1N aqueous sodium hydroxide solution twice
7. dry with materialdried over anhydrous sodium sulfate
8. filtrationfiltered
9. concentrationconcentrated