Potassium Trifluoromethanesulfonate → 2-Oxobutyl-thiacyclohexanium trifluoromethanesulfonate

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Reaction Conditions

Reaction Steps

In a 300 ml three-necked flask, 2 g of 2-oxobutyl-thiacyclohexanium bromide obtained in Example 1 was dissolved in 10 ml of acetonitrile. To the solution, a solution prepared by dissolving 1.5 g of a potassium trifluoromethanesulfonate salt in 100 ml of acetonitrile was added dropwise. After stirring for three hours, the deposited potassium bromide was removed by filtration and acetonitrile was distilled off under reduced pressure by an evaporator. The residue was dissolved in chloroform and the insoluble matter was removed by filtration. Chloroform in the filtrate was distilled off under reduced pressure and the residue (transparent viscous liquid) was cooled in a refrigerator at −20° C. for three hours. The residue was converted into a white crystal by cooling. The white crystal was recrystallized from ethyl acetate and then dried under reduced pressure at 30° C. for six hours to obtain 1.92 g of 2-oxobutyl-thiacyclohexanium trifluoromethanesulfonate (yield: 75.4%).

Provenance & Evidence