反应详情

A mixture of 1.5 g (8.74 mmol) of 6-chloro-N′-hydroxypyridine-3-carboximidamide and 1.13 mL (9.18 mmol) of trimethylacetyl chloride in 15 mL of toluene is stirred for 1 hour at room temperature and then refluxed for 4 hours. The medium is filtered. The insoluble material formed is dissolved in 15 mL of AcOH and then heated at 60° C. for 5 hours. After cooling to room temperature, the medium is concentrated under reduced pressure and then purified by chromatography on silica gel, eluting with a cyclohexane/EtOAc mixture (9/1). 0.39 g of 5-(5-tert-butyl-1,2,4-oxadiazol-3-yl)-2-chloropyridine is obtained in the form of a white solid.

1. temperaturerefluxed for 4 hours
2. filtrationThe medium is filtered
3. customThe insoluble material formed
4. temperatureheated at 60° C. for 5 hours
5. temperatureAfter cooling to room temperature
6. concentrationthe medium is concentrated under reduced pressure
7. custompurified by chromatography on silica gel
8. washeluting with a cyclohexane/EtOAc mixture (9/1)