反应详情

A solution of 1-(4-trifluoromethoxy-phenyl)-ethanone (5 g, 24 mmol) and diethyl oxalate (3.25 ml, 24 mmol) in ethanol (5 ml) was added within 20 min to an ice cooled solution of metallic sodium (552 mg, 24 mmol) in ethanol (15 ml) under an argon atmosphere. The cooling bath was removed and the reaction stirred 30 min after reaching ambient temperature. After standing 14 h, the precipitated yellow solid was filtered. The solid was partitioned between 1 M HCl/ice water 1/1 and tert butyl methyl ether. The aqueous layer was extracted two times with tert butyl methyl ether, the combined extracts were washed with brine/ice water 1/1 and dried over sodium sulfate. Evaporation of the solid gave 7.2 g (23.8 mmol, 99%) of the title compound as orange crystals.

1. customThe cooling bath was removed
2. customafter reaching ambient temperature
3. waitAfter standing 14 h
4. filtrationthe precipitated yellow solid was filtered
5. customThe solid was partitioned between 1 M HCl/ice water 1/1 and tert butyl methyl ether
6. extractionThe aqueous layer was extracted two times with tert butyl methyl ether
7. washthe combined extracts were washed with brine/ice water 1/1
8. dry with materialdried over sodium sulfate
9. customEvaporation of the solid