Ethyl Acetate → 1-formyl-2,3-dihydro-1H-imidazo[1,2-b]pyrazole

HRID 1681647Notes

Reaction equation

HRID 1681647 reaction equation
CS(O[CH2:6][CH2:7][N:8]1[C:12]([NH:13][CH:14]=[O:15])=[CH:11][CH:10]=[N:9]1)(=O)=O.[H-].[Na+].C(OCC)(=O)C>CN(C)C=O>[CH:14]([N:13]1[C:12]2[N:8]([N:9]=[CH:10][CH:11]=2)[CH2:7][CH2:6]1)=[O:15]

Participants

5

Reactant 3

HCID 8857Ethyl AcetateHCID 24758Sodium hydrideHCID 150777381-(2-Methylsulfonyloxyethyl)-5-formamidopyrazole

Product 1

HCID 150777301-formyl-2,3-dihydro-1H-imidazo[1,2-b]pyrazoleYield 107.3%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

To a solution of 1-(2-methylsulfonyloxyethyl)-5-formamidopyrazole (6.2 g) in N,N-dimethylformamide (60 ml) was added 62% sodium hydride (1.03 g) under ice-cooling. The mixture was stirred at the same condition for 3 hours. The reaction mixture was poured into ethyl acetate (300 ml) and the insoluble material was filtered off. The filtrate was evaporated under reduced pressure and the residue was subjected to column chromatography on silica gel (100 g) using a mixture of diisopropyl ether and ethyl acetate as an eluent. Fractions containing the object compound were combined and evaporated in vacuo to give 1-formyl-2,3-dihydro-1H-imidazo[1,2-b]pyrazole (3.91 g) as crystals.

Workup

  1. temperaturecooling
  2. filtrationthe insoluble material was filtered off
  3. customThe filtrate was evaporated under reduced pressure
  4. additiona mixture of diisopropyl ether and ethyl acetate as an eluent
  5. additionFractions containing the object compound
  6. customevaporated in vacuo

Sources & evidence

ORD record
ord-8612bee2d25d4f72ad4ad98fd2ab0534
Source dataset
uspto-grants-1992_12
Patent number
US05173485

Reaction notes

Loading…