反应详情

A mixture of ethyl bromopyruvate (6.82 g), 2,2,2-trifluorothioacetamide (4.52 g) and ethanol (30 ml) was refluxed for 3 hours. The reaction mixture was cooled, then ethanol was distilled off under reduced pressure. To the residue was added water (40 ml), which was subjected to extraction with ethyl acetate (60 ml×2). The extract solution was washed with water (40 ml) and dried over magnesium sulfate, then the solvent was distilled off under reduced pressure. The residue was subjected to a silica gel chromatography (2.5×45 cm), eluting with ethyl acetate-hexane (1:5). The desired fraction was concentrated to give ethyl 2-trifluoromethyl-4-thiazolecarboxylate (2.2 g) as pale yellow needles.

1. temperaturewas refluxed for 3 hours
2. temperatureThe reaction mixture was cooled
3. distillationethanol was distilled off under reduced pressure
4. additionTo the residue was added water (40 ml), which
5. extractionwas subjected to extraction with ethyl acetate (60 ml×2)
6. washThe extract solution was washed with water (40 ml)
7. dry with materialdried over magnesium sulfate
8. distillationthe solvent was distilled off under reduced pressure
9. washeluting with ethyl acetate-hexane (1:5)
10. concentrationThe desired fraction was concentrated