Water → ethyl 5-amino-1-(pyridin-2-yl)-1H-pyrazole-4-carboxylate

HRID 280448Notes

Reaction equation

HRID 280448 reaction equation
[NH:1]([C:3]1[CH:8]=[CH:7][CH:6]=[CH:5][N:4]=1)[NH2:2].[CH2:9]([O:11][C:12](=[O:20])[C:13](=[CH:16]OCC)[C:14]#[N:15])[CH3:10].O>C(O)(=O)C>[NH2:15][C:14]1[N:1]([C:3]2[CH:8]=[CH:7][CH:6]=[CH:5][N:4]=2)[N:2]=[CH:16][C:13]=1[C:12]([O:11][CH2:9][CH3:10])=[O:20]

Participants

5

Reactant 3

HCID 962WaterHCID 786452-HydrazinopyridineHCID 789432-Propenoic acid, 2-cyano-3-ethoxy-, ethyl ester

Product 1

HCID 742041ethyl 5-amino-1-(pyridin-2-yl)-1H-pyrazole-4-carboxylateYield 50.9%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

A solution of 21.83 g of 2-hydrazinopyridine and 38.2 g of ethyl(ethoxymethylene)cyanoacetate dissolved in 150 ml of acetic acid and 50 ml of water was heated on a steam bath for approximately 16 hours. The reaction mixture was allowed to cool to room temperature and placed in a refrigerator whereupon crystals slowly formed. The precipitated solid was collected by filtration and washed with cold 50% aqueous ethanol to provide 23.62 g of 5-amino-1-(2-pyridinyl)-1H-pyrazole-4-carboxylic acid, ethyl ester. Yield 50.9%. MP=89°-91° C.

Workup

  1. customslowly formed
  2. filtrationThe precipitated solid was collected by filtration
  3. washwashed with cold 50% aqueous ethanol

Sources & evidence

ORD record
ord-e7040e39863e4daa9661026a69fbdc7e
Source dataset
uspto-grants-1986_05
Patent number
US04589905

Reaction notes

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