Triethylamine → 1-Benzyl-3,5-dimethyl-1H-pyrazole

HRID 220464

Reaction equation

HRID 220464 reaction equation
[CH3:1][C:2](=O)[CH2:3][C:4](=O)[CH3:5].Cl.Cl.[CH2:10]([NH:17][NH2:18])[C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1.C(N(CC)CC)C>C(O)(=O)C>[CH2:10]([N:17]1[C:4]([CH3:5])=[CH:3][C:2]([CH3:1])=[N:18]1)[C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1

Participants

5

Reactant 3

HCID 8471TriethylamineHCID 31261AcetylacetoneHCID 146540Benzylhydrazine dihydrochloride

Product 1

HCID 6037651-Benzyl-3,5-dimethyl-1H-pyrazoleYield 92%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

Dissolve 2,4-pentanedione (5.09 g, 50.8 mmol) and benzylhydrazine dihydrochloride (10.91 g, 55.9 mmol) in acetic acid (40 mL). Slowly add triethylamine (15.6 mL, 0.112 mol) and stir the mixture for 18 hr. Concentrate the solution then dilute the residue with saturated aqueous sodium bicarbonate and extract 3 times with ethyl acetate. Dry (sodium sulfate), filter, concentrate and purify (silica gel chromatography, eluting with 40:60 hexanes:ethyl acetate), to give 1-benzyl-3,5-dimethyl-1H-pyrazole as a yellow oil (8.703 g, 92%).

Workup

  1. concentrationConcentrate the solution
  2. additionthen dilute the residue with saturated aqueous sodium bicarbonate
  3. extractionextract 3 times with ethyl acetate
  4. dry with materialDry (sodium sulfate)
  5. filtrationfilter
  6. concentrationconcentrate
  7. custompurify
  8. wash(silica gel chromatography, eluting with 40:60 hexanes:ethyl acetate)

Sources & evidence

ORD record
ord-adf012ae9ce445b39981d5845a2c7100
Source dataset
uspto-grants-2012_06
Patent number
US08202873B2

Linked notes

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