反应详情

Ethyl 3-bromo-2-oxopropanoate (2.5 mL) was added dropwise to a solution of 2-ethylbutanethioamide (example 71, step b) (3.8 g) in ethanol (100 mL) and the resulting mixture heated at reflux overnight. The solvent was evaporated and the residue partitioned between ethyl acetate (100 mL) and saturated sodium hydrogen carbonate solution (100 mL). The layers were separated and the aqueous phase extracted with ethyl acetate (2×100 mL). The combined organic solutions were washed with brine (100 mL), dried over sodium sulphate, filtered and evaporated. The residue was purified by silica gel chromatography eluting with 20:1 isohexane:ethyl acetate. The fractions containing product were combined and evaporated to give the subtitled compound as a yellow oil. Yield 2.8 g.

1. temperaturethe resulting mixture heated
2. temperatureat reflux overnight
3. customThe solvent was evaporated
4. customthe residue partitioned between ethyl acetate (100 mL) and saturated sodium hydrogen carbonate solution (100 mL)
5. customThe layers were separated
6. extractionthe aqueous phase extracted with ethyl acetate (2×100 mL)
7. washThe combined organic solutions were washed with brine (100 mL)
8. dry with materialdried over sodium sulphate
9. filtrationfiltered
10. customevaporated
11. customThe residue was purified by silica gel chromatography
12. washeluting with 20:1 isohexane
13. additionThe fractions containing product
14. customevaporated