反应详情

温度

100 °C

Pyrazin-2-amine 4a (5 g, 52 mmol) was dissolved in a 40% 2-chloroacetaldehyde solution (15 mL, 78 mmol), followed by addition of sodium bicarbonate (6.60 g, 78 mmol). After stirring for 48 hours at 100° C., the reaction mixture was cooled to room temperature, added with 100 mL of a saturated potassium carbonate solution, and extracted with dichloromethane (100 mL×3). The organic phase was combined, dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated under reduced pressure to obtain imidazo[1,2-a]pyrazine 4b (3 g, yield 50.0%) as a brown solid.

1. temperaturethe reaction mixture was cooled to room temperature
2. extractionextracted with dichloromethane (100 mL×3)
3. dry with materialdried over anhydrous sodium sulfate
4. filtrationfiltered
5. concentrationThe filtrate was concentrated under reduced pressure