Ethanol → Ethyl 5-amino-3-(2-hydroxyethoxy)-1H-pyrazole-4-carboxylate

HRID 1929755Notes

Reaction equation

HRID 1929755 reaction equation
[C:1]([C:3]([C:10]([O:12][CH2:13][CH3:14])=[O:11])=[CH:4]C1OCCO1)#[N:2].Cl.[NH2:16][NH2:17].[C:18]([O-:21])(=O)[CH3:19].[Na+].C([OH:25])C>>[NH2:2][C:1]1[C:3]([C:10]([O:12][CH2:13][CH3:14])=[O:11])=[C:4]([O:25][CH2:19][CH2:18][OH:21])[NH:17][N:16]=1

Participants

5

Reactant 4

HCID 702EthanolHCID 115031Hydrazinium chlorideHCID 517045Sodium AcetateHCID 67272950HCID 67272950, compound

Product 1

HCID 135678304Ethyl 5-amino-3-(2-hydroxyethoxy)-1H-pyrazole-4-carboxylateYield 86%

Conditions

Temperature
80 °C

Procedure

To a solution of 2-[(cyano)(ethoxycarbonyl)vinyl]-1,3-dioxolane (2.0 g) in ethanol (20 mL) was added hydrazine hydrochloride (748 mg) and sodium acetate (1.34 g) and the mixture was stirred at 80° C. (external temperature) for 1 hour. After cooling to room temperature, the reaction mixture was filtered through Cerite and the filtrate was concentrated in vacuo. The resultant crude product was purified by a column chromatography on silica gel (solvent; chloroform/methanol=100/0 to 85/15) to give 3-amino-4-ethoxycarbonyl-5-(2-hydroxy)ethoxypyrazole (2.01 g, yield: 86%) as a pale pink solid.

Workup

  1. temperatureAfter cooling to room temperature
  2. filtrationthe reaction mixture was filtered through Cerite
  3. concentrationthe filtrate was concentrated in vacuo
  4. customThe resultant crude product was purified by a column chromatography on silica gel (solvent; chloroform/methanol=100/0 to 85/15)

Sources & evidence

ORD record
ord-ed62ca91d1124901939f4a8bc9453571
Source dataset
uspto-grants-2012_05
Patent number
US08188097B2

Reaction notes

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