Water → HCID 19890296, compound

HRID 345049Notes

Reaction equation

HRID 345049 reaction equation
[CH3:1][N:2]1[C:6]([C:7]([O:9][CH2:10][CH3:11])=[O:8])=[C:5]([OH:12])[C:4]([CH3:13])=[N:3]1.[H-].[Na+].[CH2:16](Br)[C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1.O>CN(C)C=O>[CH2:16]([O:12][C:5]1[C:4]([CH3:13])=[N:3][N:2]([CH3:1])[C:6]=1[C:7]([O:9][CH2:10][CH3:11])=[O:8])[C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1

Participants

6

Reactant 4

HCID 962WaterHCID 7498Benzyl BromideHCID 24758Sodium hydrideHCID 54722006HCID 54722006, compound

Product 1

HCID 19890296HCID 19890296, compoundYield 78.4%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent2×

Procedure

To a 5 ml solution of ethyl 1,3-dimethyl-4-hydroxypyrazole-5-carboxylate (2 g, 11.6 mmol) in anhydrous dimethylformamide (hereinafter, referred to as DMF) was added sodium hydride (60 % dispersion in oil) (0.47 g, 11.8 mmol) under ice-cooling. Benzyl bromide (2 g, 11.7 mmol) was then added dropwise thereto, and the resulting mixture was stirred at room temperature for one hour and poured into water. The mixture was extracted with ethyl acetate. The extract was washed with water, and saturated brine, dried over anhydrous sodium sulfate and concentrated in vacuo. The residue was chromatographed over silica gel (eluent; ethyl acetate/n-hexane=1:4) to give ethyl 4-benzyloxy -1,3-dimethylpyrazol-5-carboxylate (2.5 g, 9.1 mmol, 78 %).

Workup

  1. temperaturecooling
  2. extractionThe mixture was extracted with ethyl acetate
  3. washThe extract was washed with water, and saturated brine
  4. dry with materialdried over anhydrous sodium sulfate
  5. concentrationconcentrated in vacuo
  6. customThe residue was chromatographed over silica gel (eluent; ethyl acetate/n-hexane=1:4)

Sources & evidence

ORD record
ord-5228db06e4374984ac941f4bf45be110
Source dataset
uspto-grants-1991_10
Patent number
US05055477

Reaction notes

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