Dimethylformamide → ethyl 1-benzyl-3-benzyloxy-1H-pyrazole-4-carboxylate

HRID 1295240Notes

Reaction equation

HRID 1295240 reaction equation
[OH:1][C:2]1[C:6]([C:7]([O:9][CH2:10][CH3:11])=[O:8])=[CH:5][NH:4][N:3]=1.[CH2:12](Br)[C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1.C(=O)([O-])[O-].[K+].[K+].CN(C)C=O>O>[CH2:12]([N:4]1[CH:5]=[C:6]([C:7]([O:9][CH2:10][CH3:11])=[O:8])[C:2]([O:1][CH2:12][C:13]2[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=2)=[N:3]1)[C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1

Participants

6

Reactant 4

HCID 6228DimethylformamideHCID 7498Benzyl BromideHCID 11430Potassium CarbonateHCID 178469940HCID 178469940, compound

Product 1

HCID 22930773ethyl 1-benzyl-3-benzyloxy-1H-pyrazole-4-carboxylateYield 95%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
80 °C

Procedure

A mixture of ethyl 3-hydroxy-1H-pyrazole-4-carboxylate (11.53 g), benzyl bromide (18 ml), potassium carbonate (21.12 g) and N,N-dimethylformamide (300 ml) was stirred at 80° C. for 5 hrs. The reaction mixture was poured into water and the mixture was extracted with ethyl acetate. The ethyl acetate layer was dilute hydrochloric acid, then washed successively with saturated brine, dried (MgSO4) and concentrated. The residue was subjected to silica gel column chromatography, and ethyl 1-benzyl-3-benzyloxy-1H-pyrazole-4-carboxylate (13.52 g, yield 95%) was obtained as colorless crystals from a fraction eluted with ethyl acetate-hexane (1:4, volume ratio). The crystals were recrystallized from ethyl acetate-hexane. melting point: 71–72° C.

Workup

  1. extractionthe mixture was extracted with ethyl acetate
  2. washwashed successively with saturated brine
  3. dry with materialdried (MgSO4)
  4. concentrationconcentrated

Sources & evidence

ORD record
ord-60c55390054f4ecca47a0105f0581080
Source dataset
uspto-grants-2007_07
Patent number
US07241785B2

Reaction notes

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