Reaktion #976848

Reaktionsgleichung

potassium

imidazole

1-(1,1,2,2-tetrafluoroethyl)imidazole

ethyl trifluoroacetate

→

1-(1,2,2-trifluoroethenyl)imidazole

Ausbeute 13.0%

Lösungsmittel

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeAfter the inside of a system was evacuated
2. 2
   workup.ADDITIONTFE was introduced until the inside pressure of the system
3. 3
   TemperaturThen the temperature of the reaction system was increased to 100° C.
4. 4
   workup.ADDITIONTFE was further introduced
5. 5
   Temperaturto maintain the inside pressure of the reaction system at 0.3 to 0.5 MPa·G
6. 6
   Sonstigewas continued at 100° C
7. 7
   SonstigeFifteen hours
8. 8
   Sonstigewas brought to room temperature
9. 9
   Sonstigeto terminate
10. 10
    Sonstigethe reaction
11. 11
    SonstigeTo this crude reaction product

Vorschrift

Into a 50 ml autoclave were poured 10.6 g (100 mmol) of potassium salt of imidazole and tetrahydrofuran (30 ml), and the inside of the autoclave was cooled to −78° C., and evacuation and replacement of atmosphere in the autoclave with nitrogen gas were carried out three times. After the inside of a system was evacuated, TFE was introduced until the inside pressure of the system reached 0.1 MPa·G. Then the temperature of the reaction system was increased to 100° C., and TFE was further introduced to maintain the inside pressure of the reaction system at 0.3 to 0.5 MPa·G. Supply of TFE was stopped when the amount of TFE reached 1.1 equivalents (11 g=110 mmol) to the potassium salt of imidazole, and stirring was continued at 100° C. Fifteen hours after starting of the stirring, the inside of the reaction system was brought to room temperature, followed by evacuation to terminate the reaction. To this crude reaction product was added 2.84 g (20 mmol) of ethyl trifluoroacetate, and it was confirmed by a 19F-NMR analysis based on ethyl trifluoroacetate that 1-(1,1,2,2-tetrafluoroethyl)imidazole had been produced at yield of 13% and 1-(1,2,2-trifluoroethenyl)imidazole had been produced at yield of 56%. Also according to gas chromatography analysis, it was confirmed that the remaining imidazole was 14%.

Quelle