Water → 2,3-dihydro-1H-imidazo[1,2-b]pyrazole-1,7-dicarbaldehyde

HRID 349568Notes

Reaction equation

HRID 349568 reaction equation
P(Cl)(Cl)(Cl)=O.[N:6]1([CH:14]=[O:15])[C:13]2[N:9]([N:10]=[CH:11][CH:12]=2)[CH2:8][CH2:7]1.[C:16](OCC)(=[O:18])C.O>CN(C)C=O>[N:6]1([CH:14]=[O:15])[C:13]2[N:9]([N:10]=[CH:11][C:12]=2[CH:16]=[O:18])[CH2:8][CH2:7]1

Participants

6

Reactant 4

HCID 962WaterHCID 8857Ethyl AcetateHCID 24813Phosphorus oxychlorideHCID 150777301-formyl-2,3-dihydro-1H-imidazo[1,2-b]pyrazole

Product 1

HCID 179619742,3-dihydro-1H-imidazo[1,2-b]pyrazole-1,7-dicarbaldehyde

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent2×

Procedure

To phosphoric trichloride (136 ml) was added N,N-dimethylformamide (339 ml) under ice-cooling, and the mixture was stirred under ice-cooling for 30 minutes. To the mixture was added a solution of 2,3-dihydro-1H-imidazo[1,2-b]pyrazole-1-carbaldehyde (100 g) in N,N-dimethylformamide (200 ml), and the mixture was stirred at 80° C. for 1.5 hours. The reaction mixture was carefully added to a mixture of ethyl acetate and water under ice-cooling, and the mixture was adjusted to pH 6. The organic layer was dried over anhydrous magnesium sulfate, filtered, and concentrated in vacuo. The residue was triturated with diisopropyl ether and dried in vacuo to give 2,3-dihydro-1H-imidazo[1,2-b]pyrazole-1,7-dicarbaldehyde (102 g).

Workup

  1. temperaturecooling
  2. temperaturecooling for 30 minutes
  3. stirringthe mixture was stirred at 80° C. for 1.5 hours
  4. temperaturecooling
  5. dry with materialThe organic layer was dried over anhydrous magnesium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated in vacuo
  8. customThe residue was triturated with diisopropyl ether
  9. customdried in vacuo

Sources & evidence

ORD record
ord-d08d4fc5ddd44599a6c2874947a805b5
Source dataset
uspto-grants-2007_02
Patent number
US07179801B2

Reaction notes

Loading…