反应详情

10.0 g (about 90% pure, 62.4 mmol) of 6-oxoheptanoic acid were initially charged in 71.8 ml of cyclohexane, and 20.46 g (93.6 mmol) of tert-butyl 2,2,2-trichloroacetimidate and 15 ml of dichloromethane were added. At −10° C. 0.55 ml (6.24 mmol) of trifluoromethanesulfonic acid were slowly added dropwise to the solution. The resulting suspension was stirred overnight with warming to RT. The insoluble precipitate was then removed by filtration. The filtrate was washed twice with sodium bicarbonate solution and with saturated sodium chloride solution, dried over magnesium sulfate and concentrated under reduced pressure. The residue was purified by chromatography on silica gel (mobile phase cyclohexane/ethyl acetate 5:1). On standing overnight, a solid precipitated from the product obtained in this manner. This solid was removed by filtration with suction and discarded. The target product, obtained in the form of the filtrate, was not purified any further. This gave 4.51 g (36.1% of theory) of the title compound.

1. customAt −10° C
2. customThe insoluble precipitate was then removed by filtration
3. washThe filtrate was washed twice with sodium bicarbonate solution and with saturated sodium chloride solution
4. dry with materialdried over magnesium sulfate
5. concentrationconcentrated under reduced pressure
6. customThe residue was purified by chromatography on silica gel (mobile phase cyclohexane/ethyl acetate 5:1)
7. waitOn standing overnight
8. customa solid precipitated from the product
9. customobtained in this manner
10. customThis solid was removed by filtration with suction
11. customThe target product, obtained in the form of the filtrate
12. customwas not purified any further