反应详情

3,4-Dihydroxybenzaldehyde (0.50 g, 3.62 mmol, Aldrich), methyl chlorodifluoroacetate (0.52 g, 3.62 mmol, Aldrich) and potassium carbonate (0.50 g, 3.62 mmol) were combined in DMF (5.0 mL) under an argon atmosphere. After stirring at 60°-65° C. for 3 h, DMF was removed in vacuo and the residue was partioned between aqueous 3N HCl and ether. The aqueous layer was extracted three times with ether. The combined organic extracts were washed with water, with brine, were dried (MgSO4), filtered and evaporated. The residue was purified by flash chromatography (silica gel, 25% ethyl acetate/hexanes) to provide the title compound as a white solid (0.20 g, 38%). mp 83°-85° C.

1. customDMF was removed in vacuo
2. extractionThe aqueous layer was extracted three times with ether
3. washThe combined organic extracts were washed with water, with brine
4. dry with materialwere dried (MgSO4)
5. filtrationfiltered
6. customevaporated
7. customThe residue was purified by flash chromatography (silica gel, 25% ethyl acetate/hexanes)