Hydrazine hydrate (1:1) → 1H-Pyrazole, 4,5-dihydro-3-methyl-5-phenyl-

HRID 465279Notes

Reaction equation

HRID 465279 reaction equation
O.[NH2:2][NH2:3].[C:4]1(/[CH:10]=[CH:11]/[C:12](=O)[CH3:13])[CH:9]=[CH:8][CH:7]=[CH:6][CH:5]=1>CO>[CH3:13][C:12]1[CH2:11][CH:10]([C:4]2[CH:9]=[CH:8][CH:7]=[CH:6][CH:5]=2)[NH:3][N:2]=1

Participants

4

Reactant 2

HCID 24654Hydrazine hydrate (1:1)HCID 637759Benzylideneacetone

Product 1

HCID 101301011H-Pyrazole, 4,5-dihydro-3-methyl-5-phenyl-Yield 74.8%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent2×

Procedure

17.1 g (342 mmol) of hydrazine monohydrate was dissolved in 500 ml of methanol. Then, 50 g (342 mmol) of trans-4-phenyl-3-buten-2-one dissolved in 100 ml of methanol was gradually dropwise added thereto under stirring within a range of from 5° C. to 15° C. Then, the mixture was stirred at room temperature for 30 hours, and methanol was distilled off under reduced pressure. The residue was distilled under reduced pressure to obtain 41.0 g of the desired 3-methyl-5-phenyl-2-pyrazoline.

Workup

  1. additionwas gradually dropwise added
  2. stirringThen, the mixture was stirred at room temperature for 30 hours
  3. distillationmethanol was distilled off under reduced pressure
  4. distillationThe residue was distilled under reduced pressure

Sources & evidence

ORD record
ord-e86188219a69483abe7df20cec0e3550
Source dataset
uspto-grants-1992_10
Patent number
US05152824

Reaction notes

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