反应详情

The product from above (6-fluorochromen-4-one (5.25 g, 32.0 mmol) and hydroxylamine hydrochloride (4.65 g, 67.2 mmol) are dissolved in ethanol (180 ml) and the resulting mixture is heated to reflux. The reaction is allowed to stir for 18 hours before cooling and concentrating. The residue is is taken up in toluene and filtered to give 690 mg of 4-fluoro-2-(isoxazol-5-yl)phenol and from the filtrate 594 mg of 4-fluoro-2-(isoxazol-3-yl)phenol. These phenolic products are separately reacted with (2S)-glycidyl 3-nitrobenzenesulfonate substantially as described for Epoxide 1 to yield the title epoxides.

1. temperaturethe resulting mixture is heated to reflux
2. temperaturebefore cooling
3. concentrationconcentrating
4. filtrationfiltered