反应详情

温度

120 °C

Sodium hydride (60% dispersion in mineral oil, 4.50 g, 113 mmol) was added portionwise to a solution of 3-hydroxypyridine (13.2 g, 139 mmol) and tert-butyl tetrahydro-3-oxo-1H-oxazolo[3,4-a]pyrazine-7(3H)-carboxylate (3.37 g, 13.9 mmol) in DMF (100 mL). Upon complete addition, the reaction mixture was heated to 120° C. for 60 h. Upon cooling to rt, water (10 mL) was added and the reaction mixture was concentrated under reduced pressure. The material was dissolved in H2O (150 mL) and EtOAc (100 mL). The organic layer was separated, and the aqueous layer was extracted with EtOAc (2×100 mL). The combined organics were concentrated under reduced pressure. The material was dissolved in EtOAc (150 mL) and washed with 1 N NaOH (3×50 mL) and brine (50 mL), dried over Na2SO4, filtered, and concentrated under reduced pressure. Purification by column chromatography (0 to 5% MeOH in CH2Cl2 gradient) gave 1.7096 g (42%) of the desired product as a white solid. LC-MS: RT=3.81 min, [M+H]+=294.2.

1. additionUpon complete addition
2. temperatureUpon cooling to rt
3. concentrationthe reaction mixture was concentrated under reduced pressure
4. dissolutionThe material was dissolved in H2O (150 mL)
5. customThe organic layer was separated
6. extractionthe aqueous layer was extracted with EtOAc (2×100 mL)
7. concentrationThe combined organics were concentrated under reduced pressure
8. dissolutionThe material was dissolved in EtOAc (150 mL)
9. washwashed with 1 N NaOH (3×50 mL) and brine (50 mL)
10. dry with materialdried over Na2SO4
11. filtrationfiltered
12. concentrationconcentrated under reduced pressure
13. customPurification by column chromatography (0 to 5% MeOH in CH2Cl2 gradient)