反应详情

A solution of ethyl 3-fluoro-5-(4-methoxy-3,4,5,6-tetrahydro-2H-pyran-4-yl)phenoxyacetate (Step 1) (0.3 g, 1 mmol) in ethanolic LiOH (1M, 1.5 ml) was stirred at room temperature for 2 h. The reaction mixture was diluted with 5% citric acid (10 mL) and extracted with ether (2×15 mL). The ether extracts were combined and washed with water (2×20 mL), dried (Na2SO4), filtered, and concentrated under reduced pressure to give 0.26 g (95%) of 3-fluoro-5-(4-methoxy-3,4,5,6-tetrahydro-2H-pyran-4-yl)phenoxyacetic acid as a colorless viscous liquid: 1H NMR (CDCl3/300 MHz) δ 6.78 (d, 2H, J=10.5 Hz), 6.50 (d, 1H, J=10.5 Hz), 4.68 (s, 2H), 3.82 (m, 4H), 2.99 (s, 3H), 1.92 (m, 4H); FABMS m/z=284 (M+H), HRMS calcd for for C14H17FO5 283.0982, found 283.09923.

1. extractionextracted with ether (2×15 mL)
2. washwashed with water (2×20 mL)
3. dry with materialdried (Na2SO4)
4. filtrationfiltered
5. concentrationconcentrated under reduced pressure