Triphenylphosphine → 1-tert-butyl-5-(2,2-difluoroethoxy)-3-trifluoromethyl-1H-pyrazole

HRID 854119Notes

Reaction equation

HRID 854119 reaction equation
[C:1]([N:5]1[C:9]([OH:10])=[CH:8][C:7]([C:11]([F:14])([F:13])[F:12])=[N:6]1)([CH3:4])([CH3:3])[CH3:2].C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.[F:34][CH:35]([F:38])[CH2:36]O.N(C(OC(C)C)=O)=NC(OC(C)C)=O>O1CCCC1.O>[C:1]([N:5]1[C:9]([O:10][CH2:36][CH:35]([F:38])[F:34])=[CH:8][C:7]([C:11]([F:13])([F:14])[F:12])=[N:6]1)([CH3:4])([CH3:2])[CH3:3]

Participants

7

Reactant 4

HCID 11776TriphenylphosphineHCID 75555Diisopropyl diazene-1,2-dicarboxylateHCID 1361872,2-Difluoroethan-1-olHCID 178448751HCID 178448751, compound

Product 1

HCID 230756741-tert-butyl-5-(2,2-difluoroethoxy)-3-trifluoromethyl-1H-pyrazoleYield 58.4%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 50.0 g (240.2 mmol) of 1-tert-butyl-5-hydroxy-3-trifluoromethyl-1H-pyrazole in 1000 ml of tetrahydrofuran were added 75.6 g (288.2 mmol) of triphenylphosphine and 23.7 g (288.8 mmol) of 2,2-difluoroethanol at room temperature, followed by stirring. Under ice-cooling, 58.3 g (288.3 mmol) of diisopropyl azodicarboxylate was added into the reaction solution, followed by 5 hours of stirring. After the completion of the reaction was confirmed, the reaction solution was poured into water and extracted with diethyl ether. The resulting organic layer was washed with water and dried over anhydrous magnesium sulfate. The solvent was removed by evaporation under reduced pressure and the residue was distilled under reduced pressure to obtain 38.2 g (yield: 58.4%) of 1-tert-butyl-5-(2,2-difluoroethoxy)-3-trifluoromethyl-1H-pyrazole.

Workup

  1. temperatureUnder ice-cooling
  2. stirringof stirring
  3. extractionextracted with diethyl ether
  4. washThe resulting organic layer was washed with water
  5. dry with materialdried over anhydrous magnesium sulfate
  6. customThe solvent was removed by evaporation under reduced pressure
  7. distillationthe residue was distilled under reduced pressure

Sources & evidence

ORD record
ord-b61a4e2510a548aeb295127d0ed5cb22
Source dataset
uspto-grants-2007_08
Patent number
US07256298B2

Reaction notes

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