Water → 2,3-dihydro-6-(4-fluorophenyl)-2-oxo-7-(pyridin-4-yl)-1H-imidazo[1,2-b]pyrazole

HRID 1708015Notes

Reaction equation

HRID 1708015 reaction equation
[H-].[Na+].[NH2:3][C:4]1[NH:8][N:7]=[C:6]([C:9]2[CH:14]=[CH:13][C:12]([F:15])=[CH:11][CH:10]=2)[C:5]=1[C:16]1[CH:21]=[CH:20][N:19]=[CH:18][CH:17]=1.Cl[CH2:23][C:24](OCC)=[O:25].O>CN(C)C=O>[F:15][C:12]1[CH:13]=[CH:14][C:9]([C:6]2[C:5]([C:16]3[CH:21]=[CH:20][N:19]=[CH:18][CH:17]=3)=[C:4]3[NH:3][C:24](=[O:25])[CH2:23][N:8]3[N:7]=2)=[CH:10][CH:11]=1

Participants

6

Reactant 4

HCID 962WaterHCID 7751Ethyl chloroacetateHCID 24758Sodium hydrideHCID 178509109HCID 178509109, compound

Product 1

HCID 1363784142,3-dihydro-6-(4-fluorophenyl)-2-oxo-7-(pyridin-4-yl)-1H-imidazo[1,2-b]pyrazoleYield 8.4%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent3×

Procedure

To a suspension of sodium hydride (288 mg) in N,N-dimethylformamide (20 ml) was added dropwise a solution of 5-amino-3-(4-fluorophenyl)-4-(pyridin-4-yl)pyrazole (1,524 g) in N,N-dimethylformamide (5 ml) with ice cooling. The mixture was stirred for 30 minutes and to the mixture was added a solution of ethyl chloroacetate (883 mg) in N,N-dimethylformamide (5 ml). After stirring of the mixture for 1 hour at ambient temperature, the reaction mixture was poured into water and the separated oil was extracted with dichloromethane. The extract was washed with brine, dried and concentrated in vacuo. The residue was dissolved in a solution of sodium (138 mg) in ethanol (5 ml) and the solution was refluxed for 1 hour. The reaction mixture was cooled, poured into water and neutralized with diluted hydrochloric acid. The separated oil was extracted with dichloromethane and the extract was washed with brine, dried and concentrated in vacuo. The residue was crystallized from ethanol to yield 2,3-dihydro-6-(4-fluorophenyl)-2-oxo-7-(pyridin-4-yl)-1H-imidazo[1,2-b]pyrazole (178 mg).

Workup

  1. stirringAfter stirring of the mixture for 1 hour at ambient temperature
  2. extractionthe separated oil was extracted with dichloromethane
  3. washThe extract was washed with brine
  4. customdried
  5. concentrationconcentrated in vacuo
  6. dissolutionThe residue was dissolved in a solution of sodium (138 mg) in ethanol (5 ml)
  7. temperaturethe solution was refluxed for 1 hour
  8. temperatureThe reaction mixture was cooled
  9. additionpoured into water and neutralized with diluted hydrochloric acid
  10. extractionThe separated oil was extracted with dichloromethane
  11. washthe extract was washed with brine
  12. customdried
  13. concentrationconcentrated in vacuo
  14. customThe residue was crystallized from ethanol

Sources & evidence

ORD record
ord-c47eece708bd4772a8a3cf9486c9a124
Source dataset
uspto-grants-1994_10
Patent number
US05356897

Reaction notes

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