反应详情

Sodium hydride (60% dispersion in mineral oil, 400 mg, 10 mmol) was charged and washed with hexane twice. Into this flask, 1,2-dimethoxyethane (20 ml) was added and then a solution prepared by dissolving 4-amino-1,1,1-trifluoro-3-buten-2-one (1.4 g, 10 mmol) and 3-methoxyacrylonitrile (830 mg, 10 mmol) in 1,2-dimethoxyethane (5 ml) was added dropwise under ice-cooling. After stirring the mixture at room temperature for 4 hours, the reaction mixture was poured into water (50 ml). This mixture was acidified with concentrated hydrochloric acid under ice-cooling and then extracted with ethyl acetate. The organic layers were combined, washed with saturated brine, dried over magnesium sulfate and then concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (a eluting solvent: hexane/ethyl acetate=3/1 to 1/1) to obtain 593 mg (yield 31.2%) of title compound (IIa) having a low polarity and 680 mg (yield 35.8%) of title compound (IIb) having a high polarity.

1. washwashed with hexane twice
2. additionInto this flask, 1,2-dimethoxyethane (20 ml) was added
3. customa solution prepared
4. additionwas added dropwise under ice-
5. temperaturecooling
6. temperaturecooling
7. extractionextracted with ethyl acetate
8. washwashed with saturated brine
9. dry with materialdried over magnesium sulfate
10. concentrationconcentrated under reduced pressure
11. customThe resulting residue was purified by silica gel column chromatography (a eluting solvent