反应详情

温度

85 °C

The 2,3-dimethyl-4-(1,5,9-trioxaspiro[5.5]undec-3-ylmethoxy)pyridine 1-oxide (3.31 g, 10.7 mmol) obtained in the step (10b) was mixed with acetic anhydride (30 ml, 331 mmol). The mixture was stirred at 85° C. for 1 hour and 55 minutes. After cooled to a room temperature, the reaction mixture was concentrated. To the residue, methanol (50 ml) and a 5N aqueous sodium hydroxide solution (30 ml, 150 mmol) were added and the mixture was stirred at room temperature for one hour. The reaction mixture was concentrated and the residue was separated between water and ethyl acetate. The organic layer was washed twice with a 1N aqueous sodium hydroxide solution, dried over anhydrous magnesium sulfate, filtered, and concentrated to obtain the title compound (1.97 g, yield: 59.5%) as a brown oil.

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