Reaktion #2456211

Reaktionsgleichung

ethyl trifluoroacetate

2′-trifluoromethyl-acetophenone

lithium hexamethyldisilazide

→

title compound

Ausbeute 99.0%

4,4,4-trifluoro-1-(2-trifluoromethyl-phenyl)-butane-1,3-dione

Ausbeute 99.0%

Lösungsmittel

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONAfter addition
2. 2
   Temperaturto warm to ambient temperature
3. 3
   SonstigeThe reaction mixture was quenched by slow addition of H2O (20 mL)
4. 4
   Einengenconcentrated under reduced pressure
5. 5
   SonstigeThe resulting material was transferred to a separatory funnel
6. 6
   workup.ADDITIONdiluted with Et2O (60 mL)
7. 7
   Waschenwashed with 1N HCl and brine
8. 8
   Trocknendried (MgSO4)
9. 9
   Einengenconcentrated

Vorschrift

To a stirred solution of 2′-trifluoromethyl-acetophenone (225 mL, 15.0 mmol) in THF (20 mL, anhyd) at −78° C. added dropwise a 1.0M solution of lithium hexamethyldisilazide (LiHMDS) (15.8 mL, 15.8 mmol). After 1 h the reaction mixture was cooled to −78° C. and charged dropwise with ethyl trifluoroacetate (3.6 mL, 30 mmol). After addition was complete, the reaction mixture was allowed to warm to ambient temperature. The reaction mixture was quenched by slow addition of H2O (20 mL) and concentrated under reduced pressure. The resulting material was transferred to a separatory funnel, diluted with Et2O (60 mL), washed with 1N HCl and brine, then dried (MgSO4) and concentrated to yield the title compound (4.2 g, 99%) as an amber liquid, which was used in the next step without purification. Rf: 0.15 (20% EtOAc/Hex).

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