反应详情

温度

-20 °C

480 mg of (10H-pyrazino[2,3-b][1,4]benzothiazin-8-yl)acetonitrile was suspended in a solution of dry methanol (20 ml)/dry dichloromethane and cooled to −20° C. Then dry hydrogen chloride gas was blown thereinto until saturation was attained while paying attention lest the bulk temperature exceed 0° C. Then the reaction mixture was hermetically sealed and allowed to stand under ice-cooling over day and night. Next, the solvent was distilled off under reduced pressure while maintaining the bulk temperature at room temperature or below. Then a small amount of dry methanol was added to the residue and ethyl acetate was gradually added thereto under ultrasonication. The orange crystals thus precipitated were taken up by filtration, washed with diethyl ether and dried under reduced pressure. Thus, 570 mg of the title compound was obtained.

1. customexceed 0° C
2. customThen the reaction mixture was hermetically sealed
3. temperaturecooling over day and night
4. distillationNext, the solvent was distilled off under reduced pressure
5. temperaturewhile maintaining the bulk temperature at room temperature or below
6. additionThen a small amount of dry methanol was added to the residue and ethyl acetate
7. additionwas gradually added
8. customunder ultrasonication
9. customThe orange crystals thus precipitated
10. filtrationwere taken up by filtration
11. washwashed with diethyl ether
12. customdried under reduced pressure