反应详情

p-Chloroaniline (4 g), ethyl 2-oxocyclopentanecarboxylate (4.66 ml) and p-toluenesulfonic acid hydrate (0.66 g) were dissolved in benzene (80 ml), and the mixture was subjected to dehydrating condensation reaction under refluxing for 24 hours, and the mixture was allowed to cool. The insoluble material was removed by filtration, and the filtrate was concentrated under reduced pressure to give an oily product. This oily product was dissolved in absolute methanol (60 ml) and thereto was added sodium cyanoboron hydride (13.2 g) with stirring at room temperature in 10 portions over a period of 11 days. The reaction mixture was cooled with ice and thereto was added conc. hydrochloric acid (21 ml), and the mixture was concentrated under reduced pressure. Water and ethyl acetate were added to the resultant to separate into layers. The organic layer was washed with water 3 tlmes, and concentrated again under reduced pressure. The residue was subjected to column chromatography on silica gel and eluted with a mixed solvent of chloroform/methanol [100:1 (v/v)] to give the oily desired product (3.76 g).

1. customcondensation reaction
2. temperatureunder refluxing for 24 hours
3. temperatureto cool
4. customThe insoluble material was removed by filtration
5. concentrationthe filtrate was concentrated under reduced pressure
6. customto give an oily product
7. temperatureThe reaction mixture was cooled with ice
8. concentrationthe mixture was concentrated under reduced pressure
9. additionWater and ethyl acetate were added to the resultant
10. customto separate into layers
11. washThe organic layer was washed with water 3 tlmes
12. concentrationconcentrated again under reduced pressure
13. washeluted with a mixed solvent of chloroform/methanol [100:1 (v/v)]