反应详情

To a stirred mixture of ethyl trifluoroacetoacetate (4.6 g, 0.025 mol) and acetic acid (3.0 g, 0.05 mol) at room temperature, DMF diusopropyl acetal (8.75 g, 0.05 mol) was added dropwise at a rate which maintained the reaction temperature below 35° C. After stirring the mixture at ambient temperature for 2 hours to complete the reaction (TLC), it was poured into water and extracted with ether. The ether extract was washed with water, brine solution, then dried (MgSO4), and concentrated. The residual yellow oil was column-chromatographed on silica gel (Hexanes:Ethyl acetate/7:3) to give ethyl 2-trifluoroacetyl-3-(N,N-dimethylamino)-2-propenoate (Compound 2; Rf=0.3) as the main product; 4.5 g (75%).

1. temperaturemaintained the reaction temperature below 35° C
2. customthe reaction (TLC), it
3. extractionextracted with ether
4. extractionThe ether extract
5. washwas washed with water, brine solution
6. dry with materialdried (MgSO4)
7. concentrationconcentrated
8. customThe residual yellow oil was column-chromatographed on silica gel (Hexanes:Ethyl acetate/7:3)