Hydrazine hydrate (1:1) → HCID 178420845, compound

HRID 2359057Notes

Reaction equation

HRID 2359057 reaction equation
C[N:2](C)[CH:3]=[CH:4][C:5]([C:7]1[S:8][CH:9]=[CH:10][CH:11]=1)=O.O.[NH2:14]N>C(O)C>[S:8]1[CH:9]=[CH:10][CH:11]=[C:7]1[C:5]1[CH:4]=[CH:3][NH:2][N:14]=1

Participants

4

Reactant 2

HCID 24654Hydrazine hydrate (1:1)HCID 6023993-(Dimethylamino)-1-(2-thienyl)-2-propen-1-one

Product 1

HCID 178420845HCID 178420845, compoundYield 90%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A mixture of 3-(dimethylamino)-1-(2-thienyl)prop-2-en-1-one (193 mmol) and hydrazine hydrate (396 mmol) in 50 mL ethanol was refluxed for 18 h and then allowed to cool to room temperature. The solvent was evaporated under reduced pressure and the residue was partitioned between ethyl acetate and water. The organic phase was successively washed with saturated aqueous ammonium chloride solution, saturated aqueous sodium bicarbonate solution and brine, dried over MgSO4, filtered and concentrated. The residue was recrystallized (dichloromethane/cyclohexane) to afford 26.0 g 3-(2-thienyl)-1H-pyrazole (90% yield).

Workup

  1. temperaturewas refluxed for 18 h
  2. customThe solvent was evaporated under reduced pressure
  3. customthe residue was partitioned between ethyl acetate and water
  4. washThe organic phase was successively washed with saturated aqueous ammonium chloride solution, saturated aqueous sodium bicarbonate solution and brine
  5. dry with materialdried over MgSO4
  6. filtrationfiltered
  7. concentrationconcentrated
  8. customThe residue was recrystallized (dichloromethane/cyclohexane)

Sources & evidence

ORD record
ord-e2be4d0c5c224445817bd88c623ed731
Source dataset
uspto-grants-2014_04
Patent number
US08685974B2

Reaction notes

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