Water → 6,7-dihydro-5H-pyrimido-[4,5-b][1,4]oxazine

Temperature

0 °C

In a 10 ml flask, the mixture of 5H-pyrimido-[4,5-b][1,4]oxazin-6-one (107 mg, 0.58 mmol) was dissolved in tetrahydrofuran (3 ml) and then cooled to 0° C. 1.0M Lithium aluminum hydride dissolved in tetrahydrofuran (1.15 ml, 1.2 mmol) was added thereto dropwise and the temperature was raised to room temperature and then stirred for additional 2 hours. After cooling to low temperature again, water, 10% sodium hydroxide solution and water were added in this order to quench the reaction. The mixture was filtered and the filtrate was extracted with ethyl acetate and the combined organic layer was washed with saturated saline solution, dried over anhydrous sodium sulfate (Na2SO4), filtered and evaporated under reduced pressure. The residue was purified by column chromatography on amine silica gel eluting with a solvent of dichloromethane to obtain white solid (20 mg, 25%).

1. additionwas added
2. temperaturedropwise and the temperature was raised to room temperature
3. temperatureAfter cooling to low temperature again
4. customto quench
5. customthe reaction
6. filtrationThe mixture was filtered
7. extractionthe filtrate was extracted with ethyl acetate
8. washthe combined organic layer was washed with saturated saline solution
9. dry with materialdried over anhydrous sodium sulfate (Na2SO4)
10. filtrationfiltered
11. customevaporated under reduced pressure
12. customThe residue was purified by column chromatography on amine silica gel eluting with a solvent of dichloromethane

ORD record

ord-2890eb6772c0487faa7d80fffd26976f

Source dataset

uspto-grants-2013_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08394792B2