反应详情

66 g of oxalic chloride was dissolved in 500 ml of dichloroethane, into which 61 g of dimethyl sulfoxide was gradually dropped at -67° C. 44 g of 1-cyclopropanecarbonyl-4-hydroxypiperidine dissolved in 200 ml of dichloromethane was dropped into the above solution at -67° C. At -67° C., 131 g of triethylamine was further added, followed by returning to room temperature. The resultant salt was removed by filtration and the filtrate was once concentrated, after which water was added to the concentrate, followed by extraction with ethyl acetate and drying with anhydrous magnesium sulfate. Moreover, the aqueous phase was extracted with chloroform and dried similarly. The solvent was distilled off under reduced pressure and the resultant reside was purified by the use of silica gel column chromatography (elution solvent: ethyl acetate:hexane=3:7), thereby obtaining 33 g of the intended compound (yield 76%).

1. additionwas gradually dropped at -67° C
2. additionwas dropped into the above solution at -67° C
3. customby returning to room temperature
4. customThe resultant salt was removed by filtration
5. concentrationthe filtrate was once concentrated
6. additionafter which water was added to the concentrate
7. extractionfollowed by extraction with ethyl acetate
8. dry with materialdrying with anhydrous magnesium sulfate
9. extractionMoreover, the aqueous phase was extracted with chloroform
10. customdried similarly
11. distillationThe solvent was distilled off under reduced pressure
12. customthe resultant reside was purified by the use of silica gel column chromatography (elution solvent: ethyl acetate:hexane=3:7)