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

HRID 349936Notes

Reaction equation

HRID 349936 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 for 5 hours at 80° C. The reaction mixture was poured into water, which was extracted with ethyl acetate. The ethyl acetate layer was washed with diluted hydrochloric acid and then with saturated aqueous sodium chloride solution, dried (MgSO4), and then 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 the fraction eluted with ethyl acetate-hexane (1:4, volume ratio). This was recrystallized from ethyl acetate-hexane. Melting point: 71–72° C.

Workup

  1. extractionwas extracted with ethyl acetate
  2. washThe ethyl acetate layer was washed with diluted hydrochloric acid
  3. dry with materialwith saturated aqueous sodium chloride solution, dried (MgSO4)
  4. concentrationconcentrated

Sources & evidence

ORD record
ord-7fed7bef9a8e4751a34d9ccfacb7615a
Source dataset
uspto-grants-2007_02
Patent number
US07179823B1

Reaction notes

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