tert-Butyl bromoacetate → tert-Butyl 4-(2,6-difluorophenyl)-4-oxobutyrate

HRID 496708

Reaction equation

HRID 496708 reaction equation
[CH3:1][C:2]([C:4]1[C:9]([F:10])=[CH:8][CH:7]=[CH:6][C:5]=1[F:11])=[O:3].C[Si]([N-][Si](C)(C)C)(C)C.[Li+].Br[CH2:23][C:24]([O:26][C:27]([CH3:30])([CH3:29])[CH3:28])=[O:25]>C1COCC1.CN1C(=O)N(C)CCC1.CCOC(C)=O>[F:11][C:5]1[CH:6]=[CH:7][CH:8]=[C:9]([F:10])[C:4]=1[C:2](=[O:3])[CH2:1][CH2:23][C:24]([O:26][C:27]([CH3:30])([CH3:29])[CH3:28])=[O:25]

Participants

7

Reactant 3

HCID 79177tert-Butyl bromoacetateHCID 836431-(2,6-Difluorophenyl)ethan-1-oneHCID 2733832Lithium Hexamethyldisilazide

Product 1

HCID 21964547tert-Butyl 4-(2,6-difluorophenyl)-4-oxobutyrate

Reagents, catalysts & solvents 3

HCID 8028TetrahydrofuranSolventHCID 8857Ethyl AcetateSolventHCID 816462(1H)-Pyrimidinone, tetrahydro-1,3-dimethyl-Solvent

Conditions

Temperature
-60 °C

Procedure

To a stirred solution of 2,6-Difluoroacetophenone (5 g, 32 mmol) in dry THF (40 ml) and DMPU (8 ml) was added a solution of lithium bis(trimethylsilyl)amide (1.0M, 45 ml) at 60° C. under argon. After stirring for 10 minutes at −60° C., tert-Butyl bromoacetate (6.99 g, 35.8 mmol) was added rapidly. The reaction mixture was stirred for an additional 10 minutes and then warmed to room temperature for 4 hours. The crude mixture was taken in EtOAc and washed with water and brine. The aqueous layer was extracted one more time with EtOAc. The combined organic layers were dried over Na2SO4, filtered, concentrated and purified by flash chromatography on a silica gel column (hex:ethyl acetate, 2:1) to provide the title compound.

Workup

  1. stirringThe reaction mixture was stirred for an additional 10 minutes
  2. temperaturewarmed to room temperature for 4 hours
  3. washwashed with water and brine
  4. extractionThe aqueous layer was extracted one more time with EtOAc
  5. dry with materialThe combined organic layers were dried over Na2SO4
  6. filtrationfiltered
  7. concentrationconcentrated
  8. custompurified by flash chromatography on a silica gel column (hex:ethyl acetate, 2:1)

Sources & evidence

ORD record
ord-75c5547bbc3e4b39aeea5bb4d92c18bf
Source dataset
uspto-grants-2005_09
Patent number
US06946491B2

Linked notes

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