4-nitro-1H-pyrazole → HCID 20038763, compound

HRID 1904264Notes

Reaction equation

HRID 1904264 reaction equation
[N+:1]([C:4]1[CH:5]=[N:6][NH:7][CH:8]=1)([O-])=O.[H][H].[CH3:11][CH2:12][O:13][C:14]([CH:16]1[C:21](=O)[CH2:20][CH2:19][CH2:18][CH2:17]1)=[O:15]>C(O)C.[Pd]>[NH:6]1[CH:5]=[C:4]([NH:1][CH:17]2[CH2:18][CH2:19][CH2:20][CH2:21][CH:16]2[C:14]([O:13][CH2:12][CH3:11])=[O:15])[CH:8]=[N:7]1

Participants

6

Reactant 3

HCID 163764-nitro-1H-pyrazoleHCID 95543Ethyl 2-oxocyclohexanecarboxylateHCID 178418361HCID 178418361, compound

Product 1

HCID 20038763HCID 20038763, compoundYield 90%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 702EthanolSolvent

Procedure

A solution of 4-nitropyrazole (5.2 g, 0.046 mole) in ethanol (150 ml) was hydrogenated over a 10% Pd/C catalyst (0.5 g) at atmospheric temperature and pressure until the uptake of hydrogen ceased. The catalyst was filtered off and the filtrate treated with ethyl 2-cyclohexanonecarboxylate (7.3 ml, 0.046 mole), before evaporating to dryness. A few drops of concentrated hydrochloric acid (0.1 ml) were added to the yellow oil, which was then heated on the steam bath under nitrogen for 10 minutes. The mixture was dissolved in ethyl acetate, washed with aqueous sodium hydrogen carbonate solution and water, then dried (MgSO4) and concentrated to leave a yellow solid. This was recrystallised from ether/60°-80° petroleum ether to give the title compound as a white solid (9.7 g, 90%), m.p. 92°-94° C. Found: C, 61.20; H, 7.35; N, 18.00% C12H17N3O2 requires C, 61.25; H, 7.30; N, 17.85%

Workup

  1. filtrationThe catalyst was filtered off
  2. custombefore evaporating to dryness
  3. additionA few drops of concentrated hydrochloric acid (0.1 ml) were added to the yellow oil, which
  4. temperaturewas then heated on the steam bath under nitrogen for 10 minutes
  5. dissolutionThe mixture was dissolved in ethyl acetate
  6. washwashed with aqueous sodium hydrogen carbonate solution and water
  7. dry with materialdried (MgSO4)
  8. concentrationconcentrated
  9. customto leave a yellow solid
  10. customThis was recrystallised from ether/60°-80° petroleum ether

Sources & evidence

ORD record
ord-a5985fdf1e7544bea7b0a038865af832
Source dataset
uspto-grants-1989_06
Patent number
US04837238

Reaction notes

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