Water → 2H,3H,4H-pyrido[4,3-b][1,4]oxazin-3-one

In a 500 ml flask equipped with a reflux apparatus, 3-amino-pyridin-4-ol (7.8 g, 71 mmol) was dissolved in N,N-dimethyl formamide (350 ml). To the reaction solution was added chloroacetyl chloride (6.2 ml, 78 mmol) dropwise at room temperature and then stirred at room temperature for 30 minutes. Potassium carbonate (24 g, 177 mmol) was added thereto and the mixture was heated at 100□ for 40 hours. After completion of the reaction, water was added thereto. The mixture was extracted with ethyl acetate. The combined organic layer was dried over anhydrous sodium sulfate (Na2SO4), filtered and evaporated under reduced pressure. The residue was purified by recrystallizing from solvents of ethyl acetate and n-hexane to obtain white solid (5.6 g, 53%).

1. temperaturethe mixture was heated at 100□ for 40 hours
2. additionwas added
3. extractionThe mixture was extracted with ethyl acetate
4. dry with materialThe combined organic layer was dried over anhydrous sodium sulfate (Na2SO4)
5. filtrationfiltered
6. customevaporated under reduced pressure
7. customThe residue was purified
8. customby recrystallizing from solvents of ethyl acetate and n-hexane

ORD record

ord-bc541c16604643c5b9a7e626bd084276

Source dataset

uspto-grants-2013_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08394792B2