反应详情

To 2.0 g of 3-ethoxycarbonylmethyl-2-isopropylidenehydrazonothiazilidin-4-one obtained in step (1) of Example 9 was added 30 ml of 0.5N hydrochloric acid, and the mixture was subjected to steam distillation for 15 minutes. The reaction mixture obtained was cooled, the resulting precipitates were distilled off, and the filtrate was concentrated under reduced pressure. To the residue formed were added a saturated sodium hydrogencarbonate solution and chloroform to distribute the residue between them. The organic layer was washed three times with water, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The residue formed was charged on silica gel column chromatography and eluted with a mixture of chloroform and ethyl acetate at 4:1 by volume to obtain 870 mg of 3-ethoxycarbonylmethyl-2-hydrazonothiazolidin-4-one.

1. distillationthe mixture was subjected to steam distillation for 15 minutes
2. customThe reaction mixture obtained
3. temperaturewas cooled
4. customthe resulting precipitates
5. distillationwere distilled off
6. concentrationthe filtrate was concentrated under reduced pressure
7. customTo the residue formed
8. washThe organic layer was washed three times with water
9. dry with materialdried over anhydrous magnesium sulfate
10. concentrationconcentrated under reduced pressure
11. customThe residue formed
12. additionwas charged on silica gel column chromatography
13. washeluted with a mixture of chloroform and ethyl acetate at 4:1 by volume