反应详情

A mixture of 19.99 g ethyl 4-bromo-2,3,5,6-tetrafluorobenzoylacetate and 7.8 ml DMF dimethyl acetal in 60 ml tetrahydrofuran was stirred at room temperature for about 16 hours. The mixture was then cooled in an ice-bath and 4.6 ml (S)-2-amino-1-propanol was added. The resulting clear solution was concentrated in vacuo, and the residue was dissolved in ether and chromatographed on a column of silica gel using ether as eluant. There was obtained 22.4 g of ethyl (S)-2-(4-bromo-2,3,5,6-tetrafluorobenzoyl)-N-(1-hydroxy-2-propyl)-3-aminopropenoate as a light yellow solid, m.p. 127°-134° C., [α]D25 =+17.6°.

1. temperatureThe mixture was then cooled in an ice-bath
2. concentrationThe resulting clear solution was concentrated in vacuo
3. dissolutionthe residue was dissolved in ether
4. customchromatographed on a column of silica gel