反应详情

A suspension of 5-fluoro-2-methoxy-phenylamine (3.3 g, 23 mmol), 3-oxo-butyric acid ethyl ester (3.0 g, 23 mmol), acetic acid (120 μL), and Drierite® (12.0 g) in ethanol (20 mL) was heated to reflux for 5 d. The reaction mixture was cooled to room temperature and filtered. The filtrate was concentrated in vacuo and purified by flash chromatography on silica gel (elution with EA/hexane 1:3) to give crude 3-(5-fluoro-2-methoxy-phenylamino)-but-2-enoic acid ethyl ester.

1. temperaturewas heated
2. temperatureto reflux for 5 d
3. filtrationfiltered
4. concentrationThe filtrate was concentrated in vacuo
5. custompurified by flash chromatography on silica gel (elution with EA/hexane 1:3)