2-Hydrazinopyridine → 3,5-dimethyl-1-pyridin-2-yl-1H-pyrazole-4-carboxylic acid ethyl ester

HRID 220469

Reaction equation

HRID 220469 reaction equation
[CH2:1]([O:3][C:4](=[O:12])[CH:5]([C:9](=O)[CH3:10])[C:6](=O)[CH3:7])[CH3:2].[N:13]1[CH:18]=[CH:17][CH:16]=[CH:15][C:14]=1[NH:19][NH2:20]>C(O)(=O)C>[CH2:1]([O:3][C:4]([C:5]1[C:9]([CH3:10])=[N:20][N:19]([C:14]2[CH:15]=[CH:16][CH:17]=[CH:18][N:13]=2)[C:6]=1[CH3:7])=[O:12])[CH3:2]

Participants

4

Reactant 2

HCID 786452-HydrazinopyridineHCID 79063Ethyl 2-acetylacetoacetate

Product 1

HCID 98562563,5-dimethyl-1-pyridin-2-yl-1H-pyrazole-4-carboxylic acid ethyl esterYield 97.2%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

Dissolve 2-acetyl-3-oxobutyric acid ethyl ester (20.74 g, 0.120 mol) and 2-pyridylhydrazine (14.5 mL, 0.133 mol) in acetic acid (160 mL) and stir the mixture for 18 hr. Concentrate, dilute with DCM, wash with saturated sodium bicarbonate, dry (sodium sulfate), filter and concentrate to give 3,5-dimethyl-1-pyridin-2-yl-1H-pyrazole-4-carboxylic acid ethyl ester as an oil (28.6 g, 97%). MS (APCI): m/z=246 [M+H]+.

Workup

  1. concentrationConcentrate
  2. additiondilute with DCM
  3. washwash with saturated sodium bicarbonate
  4. dry with materialdry (sodium sulfate)
  5. filtrationfilter
  6. concentrationconcentrate

Sources & evidence

ORD record
ord-8084db007efd497d9560deff49f3af73
Source dataset
uspto-grants-2012_06
Patent number
US08202873B2

Linked notes

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