Hydrochloric Acid → 5-(4-Aminophenyl)pyrazin-2(1H)-one

HRID 542458Notes

Reaction equation

HRID 542458 reaction equation
[N+:1]([C:4]1[CH:9]=[CH:8][C:7]([C:10]2[N:11]=[CH:12][C:13](=[O:16])[NH:14][CH:15]=2)=[CH:6][CH:5]=1)([O-])=O.O.NN.O.Cl>C(O)C.[Pd]>[NH2:1][C:4]1[CH:5]=[CH:6][C:7]([C:10]2[N:11]=[CH:12][C:13](=[O:16])[NH:14][CH:15]=2)=[CH:8][CH:9]=1

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 962Water3×HCID 24654Hydrazine hydrate (1:1)HCID 138535735-(4-Nitrophenyl)pyrazin-2(1H)-one

Product 1

HCID 123580285-(4-Aminophenyl)pyrazin-2(1H)-oneYield 69.6%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 702EthanolSolvent

Procedure

5-(4-Nitrophenyl)-2-(1H)-pyrazinone (0.1 g) was warmed with hydrazine hydrate (1 ml) in 50% aqueous ethanol (2.5 ml). Water (about 3 ml) was added sufficient to provide a clear solution. The mixture was allowed to cool slightly and 10% Palladium on charcoal (0.01 g) added as a slurry in a small amount of water. The well-stirred mixture was re-heated for 2 minutes, stirred without heating for 2 minutes, cooled and filtered. The filtrate was evaporated under reduced pressure to give a residue which was suspended in a little water. Dilute hydrochloric acid was added to pH6; the pale yellow solid was collected and washed with water to afford 5-(4-aminophenyl)-2(1H)-pyrazinone (0.06 g).

Workup

  1. customto provide a clear solution
  2. temperatureto cool slightly
  3. temperatureThe well-stirred mixture was re-heated for 2 minutes
  4. temperaturewithout heating for 2 minutes
  5. temperaturecooled
  6. filtrationfiltered
  7. customThe filtrate was evaporated under reduced pressure
  8. customto give a residue which
  9. customthe pale yellow solid was collected
  10. washwashed with water

Sources & evidence

ORD record
ord-2945595124be4f9aa30c47a2db18a819
Source dataset
uspto-grants-1987_04
Patent number
US04657906

Reaction notes

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