反应详情

To a stirred solution of methyl 4-(N-tert-butyloxy-carbonyl-4-piperidinyloxy)-2-(2,2,2-trifluoroethoxy)phenylacetate (3.0 g, MW=435, 6.90 mmol) from Step 7 above in MeOH (25 mL) was added a solution of aqueous NaOH (6.9 mL of a 2.0 N solution, 13.8 mmol). The mixture was refluxed for 3 h and then cooled to ambient temperature. The solvents were removed under reduced pressure and the residue was partitioned between EtOAc (100 mL) and 0.25 M aqueous citric acid (75 mL). The organic phase was separated and washed with H2O (25 mL) and brine (25 mL). The organic phase was dried (MgSO4), filtered, and the solvent was removed under reduced pressure. 4-(N-tert-butyloxycarbonyl-4-piperidinyloxy)-2-(2,2,2-trifluoroethoxy)phenylacetic acid was obtained as an amorphous solid (HPLC retention time=9.4 min (method A)).

1. temperatureThe mixture was refluxed for 3 h
2. customThe solvents were removed under reduced pressure
3. customthe residue was partitioned between EtOAc (100 mL) and 0.25 M aqueous citric acid (75 mL)
4. customThe organic phase was separated
5. washwashed with H2O (25 mL) and brine (25 mL)
6. dry with materialThe organic phase was dried (MgSO4)
7. filtrationfiltered
8. customthe solvent was removed under reduced pressure