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

HRID 1249433Notes

Reaction equation

HRID 1249433 reaction equation
[NH:1]([C:3]1[CH:8]=[CH:7][CH:6]=[CH:5][N:4]=1)[NH2:2].C(O[CH:12]=[C:13]([C:19]#[N:20])[C:14]([O:16][CH2:17][CH3:18])=[O:15])C.O>C(O)(=O)C>[NH2:20][C:19]1[N:1]([C:3]2[CH:8]=[CH:7][CH:6]=[CH:5][N:4]=2)[N:2]=[CH:12][C:13]=1[C:14]([O:16][CH2:17][CH3:18])=[O:15]

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 23.6 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-9d6e9ca566214f5aa02da7a5114e566a
Source dataset
uspto-grants-1986_12
Patent number
US04631343

Reaction notes

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