反应详情

To a 20 mL round-bottomed flask equipped for magnetic stirring and fitted with a reflux condenser was added 2-(4-{2-[2-(4′-fluorobiphenyl-4-yl)-5-methyloxazol-4-yl]ethoxy}phenoxy)-2-methylpropionic acid ethyl ester (0.268 mmoles), lithium hydroxide (0.535 mmoles, 0.268 mL of a 2N solution), and ethanol (5 mL). This solution was heated to reflux for 2 h. Distilled water was added to the mixture and the pH was adjusted to 3 using a 1N HCl solution. The organic layer was extracted with ethyl acetate, washed with brine, and concentrated in-vacuo. This crude oil was re-solvated in pure ethyl acetate and filtered over a pad of Celite. The filtrate was concentrated in-vacuo, and the crude oil was crystallized using acetonitrile. The crystals were collected and dried in-vacuo affording 2-(4-{2-[2-(4′-fluorobiphenyl-4-yl)-5-methyloxazol-4-yl]ethoxy}phenoxy)-2-methylpropionic acid. 1H NMR (400 MHz, CDCl3) 8.02 (2H, m), 7.64 (4H, m), 7.59 (2H, m), 7.13 (2H, m), 6.89 (2H, d), 6.78 (2H, d), 4.16 (2H, t), 3.00 (2H, t) 2.39 (3H, s), 1.53 (6H, s).

1. customTo a 20 mL round-bottomed flask equipped
2. customfitted with a reflux condenser
3. temperatureThis solution was heated
4. temperatureto reflux for 2 h
5. extractionThe organic layer was extracted with ethyl acetate
6. washwashed with brine
7. concentrationconcentrated in-vacuo
8. filtrationfiltered over a pad of Celite
9. concentrationThe filtrate was concentrated in-vacuo
10. customthe crude oil was crystallized
11. customThe crystals were collected
12. customdried in-vacuo