Sodium Hydroxide → 3-Phenyl-4,5-dihydro-1H-pyrazole

HRID 12491

Reaction equation

HRID 12491 reaction equation
Cl.C[N:3](C)[CH2:4][CH2:5][C:6]([C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1)=O.O.[NH2:16]N.[OH-].[Na+]>CO>[C:8]1([C:6]2[CH2:5][CH2:4][NH:3][N:16]=2)[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1

Participants

5

Reactant 3

HCID 14798Sodium HydroxideHCID 24654Hydrazine hydrate (1:1)HCID 928441-Propanone, 3-(dimethylamino)-1-phenyl-, hydrochloride (1:1)

Product 1

HCID 5897453-Phenyl-4,5-dihydro-1H-pyrazole

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent2×

Conditions

Temperature
50 °C

Procedure

Under N2 atmosphere, 3-dimethylamino-1-phenyl-propan-1-one hydrochloride (37.2 g) was dissolved in warm MeOH (75 mL), and slowly added to a solution of hydrazine hydrate (23 mL) and 50% aqueous NaOH (12 mL) in MeOH (30 mL) stirred at 50° C. The mixture was refluxed for 2 hours and evaporated under reduced pressure. Ice water was added to the residue and after stirring for 5 minutes the formed solid was filtered off. The residue was taken up in Et2O, dried over Na2SO4, and evaporated to dryness under reduced pressure to give 19.7 g of a yellow oil being 80% pure, which was used in subsequent steps without further purification.

Workup

  1. temperatureThe mixture was refluxed for 2 hours
  2. customevaporated under reduced pressure
  3. additionIce water was added to the residue
  4. stirringafter stirring for 5 minutes the formed solid
  5. filtrationwas filtered off
  6. dry with materialdried over Na2SO4
  7. customevaporated to dryness under reduced pressure

Sources & evidence

ORD record
ord-97522613bb9a4da1bcaf9856395657d5
Source dataset
uspto-grants-2010_06
Patent number
US07728018B2

Linked notes

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