反应详情

(R/S)-Ethyl 2-hydroxy-2-(4-(5-(5-phenyl-4-(trifluoromethyl)isoxazol-3-yl)-1,2,4-oxadiazol-3-yl)phenyl)acetate (Int-VIII, 380 mg, 0.83 mmol) was dissolved in THF (5.00 mL) and MeOH (5 mL). Then, 1N LiOH (0.83 mL, 0.83 mmol) was added. It was stirred for 20 min and additional 1N LiOH (0.83 mL, 0.83 mmol) was added. After stirring for 15 min, the solution was neutralized by 1N HCl to pH=5. The reaction mixture was concentrated and then EtOAc was added. The EtOAc was washed with brine. The organic layer was dried, filtered and concentrated to give (R/S)-2-hydroxy-2-(4-(5-(5-phenyl-4-(trifluoromethyl)isoxazol-3-yl)-1,2,4-oxadiazol-3-yl)phenyl)acetic acid (Int-IX, 376 mg, 0.785 mmol, 95% yield): LCMS=432.1 [M+H]+; 1H NMR (400 MHz, methanol-d4) δ ppm 8.02-8.20 (2 H, m), 7.49-7.79 (7 H, m), 5.27 (1 H, s).

1. stirringAfter stirring for 15 min
2. concentrationThe reaction mixture was concentrated
3. additionEtOAc was added
4. washThe EtOAc was washed with brine
5. customThe organic layer was dried
6. filtrationfiltered
7. concentrationconcentrated