反应详情

50% Sodium hydride (4.8 g, 0.1 mol) was washed with petroleum ether and suspended in dry tetrahydrofuran (50 ml) under nitrogen at -10° C. Ethyl3-(2-methoxyphenylamino)acrylate (22.4 g. 0.1 mol) in dry tetrahydrofuran (70 ml) was added dropwise to the suspension keeping the temperature to below 0° C. Cooling was removed and the mixture was stirred at ambient temperature until a deep orange colour was obtained. The mixture was recooled to -20° C. and treated dropwise with a solution of isobutyryl chloride (11.0 ml, 0.11 mol) in dry tetrahydrofuran (30 ml). The cooling bath was again removed, and the mixture stirred overnight at room temperature. The solvent was evaporated and the residue was dissolved in dichloromethane and washed with dilute hydrochloric acid and brine, dried, filtered and evaporated. The crude product was chromatographed (silica gel, petroleum ether/dichloromethane) to afford ethyl 2-isobutyryl-3-(2-methoxyphenylamino)acrylate as an oil (22.6 g, 77.5%).

1. customto below 0° C
2. temperatureCooling
3. customwas removed
4. customwas obtained
5. customwas recooled to -20° C.
6. customThe cooling bath was again removed
7. stirringthe mixture stirred overnight at room temperature
8. customThe solvent was evaporated
9. dissolutionthe residue was dissolved in dichloromethane
10. washwashed with dilute hydrochloric acid and brine
11. customdried
12. filtrationfiltered
13. customevaporated
14. customThe crude product was chromatographed (silica gel, petroleum ether/dichloromethane)