Hydrochloric Acid → 2-(4-Aminophenyl)-5-methyl-2,4-dihydro-3H-pyrazol-3-one dihydrochloride

HRID 1290561

Reaction equation

HRID 1290561 reaction equation
[CH3:1][C:2]1[CH2:6][C:5](=[O:7])[N:4]([C:8]2[CH:13]=[CH:12][C:11]([N+:14]([O-])=O)=[CH:10][CH:9]=2)[N:3]=1.[ClH:17]>[Pd].CO>[ClH:17].[ClH:17].[NH2:14][C:11]1[CH:10]=[CH:9][C:8]([N:4]2[C:5](=[O:7])[CH2:6][C:2]([CH3:1])=[N:3]2)=[CH:13][CH:12]=1

Participants

5

Reactant 2

HCID 313Hydrochloric AcidHCID 808163H-Pyrazol-3-one, 2,4-dihydro-5-methyl-2-(4-nitrophenyl)-

Product 1

HCID 125543512-(4-Aminophenyl)-5-methyl-2,4-dihydro-3H-pyrazol-3-one dihydrochlorideYield 68%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 887MethanolSolvent

Procedure

Into 310 ml of methanol, 500 mg of 3-methyl-1-(4-nitrophenyl)-2-pyrazolin-5-one was dissolved, 50 mg of 5% Pd/C and 0.6 ml of conc. hydrochloric acid were added to the solution, and the mixture was stirred under hydrogen atmosphere to consume the calculated amount of hydrogen. Then, the catalyst was filtered off and the filtrate was concentrated. The residue was recrystallized from methanol-ethyl ether to give 409 mg of 1-(4-aminophenyl)-3-methyl-2-pyrazolin-5-one dihydrochloride (Compound No. 50) as pale brown crystals.

Workup

  1. customto consume the calculated amount of hydrogen
  2. filtrationThen, the catalyst was filtered off
  3. concentrationthe filtrate was concentrated
  4. customThe residue was recrystallized from methanol-ethyl ether

Sources & evidence

ORD record
ord-c414a4f8e1d34e24a585075ee8f82241
Source dataset
uspto-grants-1998_05
Patent number
USRE035801

Linked notes

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