反应详情

tert-Butyl 1,3-dioxotetrahydro-1H-oxazolo[3,4-a]pyrazine-7(3H)-carboxylate (1.50 g, 5.85 mmol) and 3-aminopyridine (1.10 g, 11.7 mmol) were heated to reflux in THF (20 mL). After 4 h, the reaction mixture was cooled to rt, diluted with H2O (50 mL), and was extracted with EtOAc (3×75 mL). The combined extracts were dried over Na2SO4, filtered, and concentrated under reduced pressure. The material was purified by column chromatography (0 to 8% MeOH in CH2Cl2 with 0.5% NH4OH gradient), yielding 0.740 g (44%) of the title compound. LC-MS: RT=4.14 min, [M+H]+=307.1.

1. extractionwas extracted with EtOAc (3×75 mL)
2. dry with materialThe combined extracts were dried over Na2SO4
3. filtrationfiltered
4. concentrationconcentrated under reduced pressure
5. customThe material was purified by column chromatography (0 to 8% MeOH in CH2Cl2 with 0.5% NH4OH gradient)