Bromopinacolone → 5-(3,3-Dimethyl-2-oxo-butoxy)-1-phenyl-1H-pyrazole-3-carboxylic acid

HRID 1908634Notes

Reaction equation

HRID 1908634 reaction equation
C([O:3][C:4]([C:6]1[CH:10]=[C:9]([OH:11])[N:8]([C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=2)[N:7]=1)=[O:5])C.[H-].[Na+].Br[CH2:21][C:22](=[O:27])[C:23]([CH3:26])([CH3:25])[CH3:24]>CN(C=O)C>[CH3:24][C:23]([CH3:26])([CH3:25])[C:22](=[O:27])[CH2:21][O:11][C:9]1[N:8]([C:12]2[CH:13]=[CH:14][CH:15]=[CH:16][CH:17]=2)[N:7]=[C:6]([C:4]([OH:3])=[O:5])[CH:10]=1

Participants

5

Reactant 3

HCID 21642BromopinacoloneHCID 24758Sodium hydrideHCID 178469352HCID 178469352, compound

Product 1

HCID 669199535-(3,3-Dimethyl-2-oxo-butoxy)-1-phenyl-1H-pyrazole-3-carboxylic acid

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

To a solution of 5 g 5-Hydroxy-1-phenyl-1H-pyrazole-3-carboxylic acid ethyl ester in 12 ml of DMF was added at 0° C. 1.29 g of sodium hydride (60% in mineral oil). After 15 min at this temperature 3.85 g of 1-Bromo-3,3-dimethyl-butan-2-one were added. After 2 h at RT the mixture was poured on ice/water and extracted with ethyl acetate. The organic phase was washed with brine and dried over sodium sulfate followed by evaporation. The residue was taken up in 20 ml of THF and treated with 21.5 ml of 2M NaOH. After 2 h, additional 15 ml 2M NaOH were added. Finally, after 3 h the THF was evaporated and the residue acidified with 2M HCl resulting in the precipitation of a gum. The gum was dissolved in ethyl acetate and coevaporated with toluene. Stirring in ethyl acetate/hepatne 1:1 gave a gummy substance which solidified on evaporation.

Workup

  1. additionAfter 2 h at RT the mixture was poured on ice/water
  2. extractionextracted with ethyl acetate
  3. washThe organic phase was washed with brine
  4. dry with materialdried over sodium sulfate
  5. customfollowed by evaporation
  6. additiontreated with 21.5 ml of 2M NaOH
  7. additionadditional 15 ml 2M NaOH were added
  8. customFinally, after 3 h the THF was evaporated
  9. customthe residue acidified with 2M HCl resulting in the precipitation of a gum
  10. dissolutionThe gum was dissolved in ethyl acetate
  11. customgave a gummy substance which
  12. customsolidified on evaporation

Sources & evidence

ORD record
ord-c818bc03fd994219901b69534a0bbabe
Source dataset
uspto-grants-2013_12
Patent number
US08598179B2

Reaction notes

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