反应详情

Acetic acid (0.06 g, 1 mmol) was added dropwise to a mixture of 3-(6-methoxy-3-oxopyrido[2,3-b]pyrazin-4(3H)-yl)propanal (synthesized with reference to WO2008/9700; 0.2 g, 0.85 mmol), 6-[(4S)-4-amino-2-oxopyrrolidin-1-yl]-2H-pyrido[3,2-b][1,4]oxazin-3(4H)-one (Reference Example 22; 0.25 g, 1.0 mmol) and N,N-dimethylformamide (4 ml). Sodium triacetoxyborohydride (0.23 g, 1.1 mmol) was gradually added under cooling on ice to the obtained mixture, which was then stirred for 10 minutes. The mixture was further stirred at room temperature for 2 hours, cooled on ice, a saturated sodium hydrogen carbonate aqueous solution was added thereto, and the resultant was extracted with dichloromethane. The organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The obtained crude product was purified by silica gel column chromatography (dichloromethane/methanol) to yield 45 mg (11%) of the title compound.

1. temperatureunder cooling on ice to the obtained mixture, which
2. stirringThe mixture was further stirred at room temperature for 2 hours
3. temperaturecooled on ice
4. extractionthe resultant was extracted with dichloromethane
5. dry with materialThe organic layer was dried over anhydrous sodium sulfate
6. concentrationconcentrated under reduced pressure
7. customThe obtained crude product
8. customwas purified by silica gel column chromatography (dichloromethane/methanol)