反应详情

To a solution of 3.8 g (21.5 mmol) of 6-chloropyridine-3-carbonyl chloride in 100 mL of toluene, in Dean-stark apparatus, are added portionwise 2.5 g (21.5 mmol) N-hydroxy-2,2-dimethylpropanimidamide, and the reaction medium is stirred for 2 hours at room temperature and then heated for 2 hours. After cooling to room temperature, the medium is concentrated under reduced pressure and purified by chromatography on silica gel, eluting with a cyclohexane/EtOAc gradient of from 0 to 10% EtOAc. 4.1 g of 5-(3-tert-butyl-1,2,4-oxadiazol-5-yl)-2-chloropyridine are obtained in the form of a white solid.

1. temperatureheated for 2 hours
2. temperatureAfter cooling to room temperature
3. concentrationthe medium is concentrated under reduced pressure
4. custompurified by chromatography on silica gel
5. washeluting with a cyclohexane/EtOAc gradient of from 0 to 10% EtOAc