反应详情

8.2 g (40 mmol) of 2-methyl-4-(4-fluorobenzylidene)-oxazol-5-one of Example (II-1) in 100 ml of toluene are heated overnight under reflux with 6.3 g (50 mmol) of 3,4,4-trifluorobut-3-enol, with the addition of 200 mg of 4-dimethylaminopyridine. After cooling, the solution is washed with water and concentrated under reduced pressure and the brown solid is chromatographed over silica gel using the system chloroform/ethyl acetate (4:1). 6.5 g (Yield 49% of theory) of 3,4,4-trifluorobut-3-enyl 3-(4-fluorophenyl)-2-acetylamino-prop-2-enoate of mp.: 116° are obtained.

1. customare heated overnight
2. temperatureAfter cooling
3. washthe solution is washed with water
4. concentrationconcentrated under reduced pressure
5. customthe brown solid is chromatographed over silica gel using the system chloroform/ethyl acetate (4:1)