反应详情

Ethyl 3-chloro-3-oxopropanoate (1.7 mL; 13.2 mmol) was added to 2,5-difluoro-N′-hydroxybenzenecarboximidamide (JRD-Fluorochemical, 1.13 g; 0.6 mmol) in pyridine (30 mL). The mixture was heated to reflux for 4 hours and the solvent removed in vacuo. The residue was taken up into DCM (20 mL) and washed with water (10 mL). The organic phase was passed through a hydrophobic frit and the solvent removed in vacuo. The residue was purified on a Biotage 25+M column, eluting with petrol containing increasing amounts of EtOAc to give ethyl 2-(3-(2,5-difluorophenyl)-1,2,4-oxadiazol-5-yl)acetate (1.24 g, 70%).

1. temperatureThe mixture was heated
2. temperatureto reflux for 4 hours
3. customthe solvent removed in vacuo
4. washwashed with water (10 mL)
5. customthe solvent removed in vacuo
6. customThe residue was purified on a Biotage 25+M column
7. washeluting with petrol containing
8. temperatureincreasing amounts of EtOAc