反应详情

Benzoyl chloride (1.60 ml, 13.8 mmol) was added to a suspension of 2-chloro-N′-hydroxyacetimidamide (1.0 g, 9.21 mmol) in DCM (25 ml), with stirring at room temperature. After 30 minutes, TEA (1.41 ml, 10.1 mmol) was added to the white suspension and the mixture was stirred for 30 additional minutes (UPLC-MS: complete conversion). The solution was diluted with DCM (20 ml) and water (30 ml) was added. The aqueous phase was extracted three times with DCM (15 ml×3) and then the combined organic phases were dried (Na2SO4) and evaporated. The crude was suspended in toluene (25 ml) and the mixture was heated to reflux for 6 h (UPLC-MS: complete conversion). The solvent was evaporated and the crude was purified by flash chromatography (petroleum ether/EtOAc=95/5) to obtain 3-(chloromethyl)-5-phenyl-1,2,4-oxadiazole (803 mg, 44.8% yield) as an off-white solid.

1. stirringthe mixture was stirred for 30 additional minutes (UPLC-MS: complete conversion)
2. additionwas added
3. extractionThe aqueous phase was extracted three times with DCM (15 ml×3)
4. dry with materialthe combined organic phases were dried (Na2SO4)
5. customevaporated
6. temperaturethe mixture was heated
7. temperatureto reflux for 6 h (UPLC-MS: complete conversion)
8. customThe solvent was evaporated
9. customthe crude was purified by flash chromatography (petroleum ether/EtOAc=95/5)