反应详情

A solution of methyl 5-(6-methylpyrazine-2-carboxamido)bicyclo[3.2.1]octane-1-carboxylate (1.28 g, 4.21 mmol) and LiOH (0.15 g, 6.25 mmol) in methanol (30 mL) and H2O (3 mL) was refluxed for two hours. After cooled to room temperature, methanol was removed under reduced pressure. The residue was partitioned between water (50 mL) and diethyl ether (50 mL) to remove organic impurities. The aqueous phase was adjusted to pH 1˜2 with 2N aq. HCl and then extracted with dichloromethane (3×50 mL). The combined organic layer was washed with water (50 mL) and brine (50 mL), dried over Na2SO4 and concentrated under reduced pressure to afford 1.11 g (91%) of 5-(6-methylpyrazine-2-carboxamido)bicyclo[3.2.1]octane-1-carboxylic acid as a white solid. ESI-MS m/z: 290 (M+H)+.

1. custommethanol was removed under reduced pressure
2. customThe residue was partitioned between water (50 mL) and diethyl ether (50 mL)
3. customto remove organic impurities
4. extractionextracted with dichloromethane (3×50 mL)
5. washThe combined organic layer was washed with water (50 mL) and brine (50 mL)
6. dry with materialdried over Na2SO4
7. concentrationconcentrated under reduced pressure