Sodium hydride → Ethyl 3-amino-2-(2-oxopentyl)pyrazol-4-carboxylate

HRID 274565Notes

Reaction equation

HRID 274565 reaction equation
[H-].[Na+].[NH2:3][C:4]1[C:8]([C:9]([O:11][CH2:12][CH3:13])=[O:10])=[CH:7][NH:6][N:5]=1.Br[CH2:15][C:16](=[O:20])[CH2:17][CH2:18][CH3:19]>CN(C=O)C>[NH2:3][C:4]1[N:5]([CH2:15][C:16](=[O:20])[CH2:17][CH2:18][CH3:19])[N:6]=[CH:7][C:8]=1[C:9]([O:11][CH2:12][CH3:13])=[O:10]

Participants

5

Reactant 3

HCID 24758Sodium hydrideHCID 100578691-Bromopentan-2-oneHCID 178469928HCID 178469928, compound

Product 1

HCID 20092995Ethyl 3-amino-2-(2-oxopentyl)pyrazol-4-carboxylateYield 45.4%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

To a mixture of sodium hydride (60% dispersion in mineral oil, 0.8 g) in DMF (50 ml) was added ethyl 3-amino-pyrazol-4-carboxylate (2.0 g) and the reaction mixture was stirred at room temperature for 15 minutes. After addition of 1-bromo-2-pentanone (4.0 g), the mixture was stirred at room temperature for 13 hours. The reaction mixture was concentrated to dryness, and the residue was dissolved in ethyl acetate-water. The organic layer was washed with water, dried and concentrated to dryness. The resulting yellow syrup was purified by column chromatography on silica gel to give pale yellow prisms (1.4 g, 45%).

Workup

  1. stirringthe mixture was stirred at room temperature for 13 hours
  2. concentrationThe reaction mixture was concentrated to dryness
  3. dissolutionthe residue was dissolved in ethyl acetate-water
  4. washThe organic layer was washed with water
  5. customdried
  6. concentrationconcentrated to dryness
  7. customThe resulting yellow syrup was purified by column chromatography on silica gel

Sources & evidence

ORD record
ord-f983fe279efb4c8381f2729c0fd64fb7
Source dataset
uspto-grants-1995_02
Patent number
US05389641

Reaction notes

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