Ethyl trifluoroacetate → 1,1,1-Trifluoro-4-(triisopropylsilyl)but-3-yn-2-one

HRID 2422497Notes

Reaction equation

HRID 2422497 reaction equation
[CH:1]([Si:4]([C:11]#[CH:12])([CH:8]([CH3:10])[CH3:9])[CH:5]([CH3:7])[CH3:6])([CH3:3])[CH3:2].[Li]CCCC.[F:18][C:19]([F:26])([F:25])[C:20](OCC)=[O:21].[NH4+].[Cl-]>C1COCC1>[F:18][C:19]([F:26])([F:25])[C:20](=[O:21])[C:12]#[C:11][Si:4]([CH:5]([CH3:6])[CH3:7])([CH:1]([CH3:3])[CH3:2])[CH:8]([CH3:10])[CH3:9]

Participants

6

Reactant 4

HCID 9794Ethyl trifluoroacetateHCID 25517Ammonium ChlorideHCID 2734682(Triisopropylsilyl)acetyleneHCID 178418339Butyllithium

Product 1

HCID 597748871,1,1-Trifluoro-4-(triisopropylsilyl)but-3-yn-2-one

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of (triisopropylsilyl)acetylene (6.50 mL, 29.0 mmol) in THF (80 mL) at −78° C. was added n-BuLi (2.5 M in hexane, 12.2 mL, 30.4 mmol) while maintaining the internal temperature below −70° C. After 30 min., ethyl trifluoroacetate (4.14 mL, 34.8 mmol) was added dropwise, keeping the internal temperature below −73° C. After 15 min. at −78° C., the mixture was allowed to reach 0° C. After 2 h, a saturated solution of NH4Cl was added. The aqueous layer was extracted with EtOAc (3×), and the combined organic layers were washed with brine, dried (Na2SO4) and concentrated affording the title compound. 1H NMR (400 MHz, acetone-d6): 1.27 (m, 3H), 1.16 (d, 18H).

Workup

  1. temperaturewhile maintaining the internal temperature below −70° C
  2. customthe internal temperature below −73° C
  3. waitAfter 15 min. at −78° C.
  4. customto reach 0° C
  5. waitAfter 2 h
  6. extractionThe aqueous layer was extracted with EtOAc (3×)
  7. washthe combined organic layers were washed with brine
  8. dry with materialdried (Na2SO4)
  9. concentrationconcentrated

Sources & evidence

ORD record
ord-d9dc1e877a124658939f85aeb106249d
Source dataset
uspto-grants-2011_06
Patent number
US07960409B2

Reaction notes

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