Acetic Anhydride → (4-((2,2-Dimethyl-1,3-dioxan-5-yl)methoxy)-3,5-dimethylpyridin-2-yl)methanol

Temperature

85 °C

The 4-((2,2-dimethyl-1,3-dioxan-5-yl)methoxy)-2,3,5-trimethylpyridine 1-oxide (5.06 g, 18 mmol) obtained in the step (11e) was mixed with acetic anhydride (50 ml, 529 mmol) and the mixture was stirred at 85° C. for 1.5 hours. After cooled to room temperature, the reaction mixture was concentrated. Methanol (50 ml) and a 5N aqueous sodium hydroxide solution (50 ml, 250 mmol) were added to the residue and the mixture was stirred at room temperature for 30 minutes. The reaction mixture was concentrated and the residue was separated between water and ethyl acetate. The organic layer was washed with a 1N aqueous sodium hydroxide solution twice and dried over anhydrous magnesium sulfate, filtered and concentrated to obtain the title compound (3.02 g, yield: 59.6%) as a brown oil.

1. temperatureAfter cooled to room temperature
2. concentrationthe reaction mixture was concentrated
3. stirringthe mixture was stirred at room temperature for 30 minutes
4. concentrationThe reaction mixture was concentrated
5. customthe residue was separated 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 magnesium sulfate
8. filtrationfiltered
9. concentrationconcentrated

ORD record

ord-e33c0a724b3f406081cd90eaf452b0e7

Source dataset

uspto-grants-2012_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08124780B2