反应详情

A mixture of methyl 3-bromo-2-oxobutanoate (16.2 g), propanethioamide (7.4 g) and ethanol (150 mL) was heated under reflux for 3 hrs. The solvent was evaporated under reduced pressure, saturated aqueous sodium hydrogen carbonate was added to the residue and the mixture was extracted with ethyl acetate. The ethyl acetate layer was washed with saturated brine, dried over anhydrous magnesium sulfate and concentrated. The residue was subjected to silica gel column chromatography and eluted with ethyl acetate-hexane (1:4, v/v) to give methyl 2-ethyl-5-methyl-1,3-thiazole-4-carboxylate as a yellow oil (8.1 g, yield 53%).

1. temperaturewas heated
2. temperatureunder reflux for 3 hrs
3. customThe solvent was evaporated under reduced pressure, saturated aqueous sodium hydrogen carbonate
4. additionwas added to the residue
5. extractionthe mixture was extracted with ethyl acetate
6. washThe ethyl acetate layer was washed with saturated brine
7. dry with materialdried over anhydrous magnesium sulfate
8. concentrationconcentrated
9. washeluted with ethyl acetate-hexane (1:4, v/v)