[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH:10]=[CH:11][C:12]=1[O:13][CH2:14][CH2:15][O:16][C:17]([F:20])([F:19])[F:18])[C:6]([O:8]C)=[O:7].[Li+].[OH-]>C1COCC1.O>[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH:10]=[CH:11][C:12]=1[O:13][CH2:14][CH2:15][O:16][C:17]([F:18])([F:19])[F:20])[C:6]([OH:8])=[O:7]Methyl 3-methoxy-4-(2-(trifluoromethoxy)ethoxy)benzoate (crude from Step 1) was dissolved in THF (5 mL) and a suspension of LiOH (550 mg, 23 mmol) in water (5 mL) was added. The mixture was stirred vigorously and heated at 60° C. for 6 h before it was concentrated to half volume. Water (5 mL) was added and the mixture was extracted with diethyl ether (1×10 mL). The aqueous layer was acidified with 4N HCl to pH 2. The resulting mixture was extracted with ethyl acetate (3×10 mL) and the combined organics were washed (1×10 mL H2O, 1×10 mL brine), dried over MgSO4 and evaporated to give 3-methoxy-4-(2-(trifluoromethoxy)ethoxy)benzoic acid (1.0 g, 82%) as a white solid. ESI-MS m/z calc. 280.1. found 281.3 (M+1)+; Retention time: 1.34 minutes (3 min run).
Wird geladen…
