Ethyl trifluoroacetate → 4,4,4-Trifluoro-1-[2-(trifluoromethyl)phenyl]butane-1,3-dione

Temperature

-78 °C

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).

1. additionAfter addition
2. temperatureto warm to ambient temperature
3. customThe reaction mixture was quenched by slow addition of H2O (20 mL)
4. concentrationconcentrated under reduced pressure
5. customThe resulting material was transferred to a separatory funnel
6. additiondiluted with Et2O (60 mL)
7. washwashed with 1N HCl and brine
8. dry with materialdried (MgSO4)
9. concentrationconcentrated

ORD record

ord-db56c05e437d4f7dbdc3fdb709af0fa5

Source dataset

uspto-grants-2014_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08703805B2