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

HRID 604305

Reaction equation

HRID 604305 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 (m/z): 246 (M+1).

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-6e784c4a9e6a48a6b1c0e590182260a1
Source dataset
uspto-grants-2011_03
Patent number
US07910588B2

Linked notes

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