Water → 5-methyl-2,3-dihydro-1H-pyrido[2,3-b][1,4]oxazine

Temperatur

0 °C

5-methyl-1H-pyrido[2,3-b][1,4]oxazin-2-one (1.5 g, 9.1 mmol) was dissolved in 20 ml of anhydrous tetrahydrofuran under nitrogen atmosphere, and then cooled to 0° C. 1.0M Lithium aluminum hydride dissolved in tetrahydrofuran (11 ml, 10.9 mmol) was added thereto dropwise and then stirred for 30 minutes. The reaction temperature was raised to room temperature and stirred for 1 hour. The reaction mixture was cooled to 0° C. again and water (0.3 ml), 10% sodium hydroxide solution (0.6 ml) and water (0.9 ml) were added thereto dropwise in this order, and then stirred vigorously at room temperature for 1 hour. The formed solid was filtered and washed with excess ethyl acetate. The filtrate was washed with water and saturated saline solution, dried over anhydrous sodium sulfate (Na2SO4), filtered and evaporated under reduced pressure to obtain 5-methyl-2,3-dihydro-1H-pyrido[2,3-b][1,4]oxazine as white solid (680 mg, 50%).

1. additionwas added
2. temperatureThe reaction temperature was raised to room temperature
3. stirringstirred for 1 hour
4. temperatureThe reaction mixture was cooled to 0° C. again
5. stirringdropwise in this order, and then stirred vigorously at room temperature for 1 hour
6. filtrationThe formed solid was filtered
7. washwashed with excess ethyl acetate
8. washThe filtrate was washed with water and saturated saline solution
9. dry with materialdried over anhydrous sodium sulfate (Na2SO4)
10. filtrationfiltered
11. customevaporated under reduced pressure

ORD-Eintrag

ord-21fa28eeeb41456a8b52afae835c60c3

Quelldatensatz

uspto-grants-2013_03

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08394792B2