Ammonium formate → 1-(4-Aminophenyl)-3-(3-pyridyl)-5-ethylpyrazole

HRID 1634127Notes

Reaction equation

HRID 1634127 reaction equation
[N+:1]([C:4]1[CH:9]=[CH:8][C:7]([N:10]2[C:14]([CH2:15][CH3:16])=[CH:13][C:12]([C:17]3[CH:18]=[N:19][CH:20]=[CH:21][CH:22]=3)=[N:11]2)=[CH:6][CH:5]=1)([O-])=O.C([O-])=O.[NH4+]>O1CCOCC1.CO.[Pd]>[NH2:1][C:4]1[CH:9]=[CH:8][C:7]([N:10]2[C:14]([CH2:15][CH3:16])=[CH:13][C:12]([C:17]3[CH:18]=[N:19][CH:20]=[CH:21][CH:22]=3)=[N:11]2)=[CH:6][CH:5]=1

Participants

6

Reactant 2

HCID 2723923Ammonium formateHCID 158808931-(4-Nitrophenyl)-3-(3-pyridinyl)-5-ethylpyrazole

Product 1

HCID 186770941-(4-Aminophenyl)-3-(3-pyridyl)-5-ethylpyrazoleYield 95.8%

Reagents, catalysts & solvents 3

HCID 23938PalladiumCatalystHCID 887MethanolSolventHCID 312751,4-DioxaneSolvent

Procedure

1-(4-Nitrophenyl)-3-(3-pyridinyl)-5-ethylpyrazole (18.0 g, 61.2 mmol) was dissolved in dioxane (200 mL) and MeOH (200 mL). The solution was treated with ammonium formate (38.6 g, 612 mmol) and 5% Pd/C (1.8 g) at room temperature for 6 hr. It was then filtered through a pad of diatomaceous earth and the cake was washed with CH3CN. The filtrate was concentrated and the residue was treated with water (200 mL). The resulting slurry was stirred at room temperature for 3 hr, and collected by filtration. The solid was washed with water and dried in an oven under house vacuum to give 1-(4-aminophenyl)-3-(3-pyridinyl)-5-ethylpyrazole (15.5 g, 95%). %). 1H NMR (CDCl3, 400 MHz) 9.05 (s, 1H), 8.53 (d, J=4.7 Hz, 1H), 8.16 (d, J=7.2 Hz, 1H), 7.30 (m, 1H), 7.23, 6.75 (ABq, J=8.1 Hz, 4H) 6.54 (s, 1H), 3.83 (bs, 2H), 2.63 (q, J=7.6 Hz, 2H), 1.25 (t, J=7.6 Hz, 3H).

Workup

  1. filtrationIt was then filtered through a pad of diatomaceous earth
  2. washthe cake was washed with CH3CN
  3. concentrationThe filtrate was concentrated
  4. additionthe residue was treated with water (200 mL)
  5. filtrationcollected by filtration
  6. washThe solid was washed with water
  7. customdried in an oven under house vacuum

Sources & evidence

ORD record
ord-589ad3074c7d4d15b878382dc8518ab1
Source dataset
uspto-grants-2003_01
Patent number
US06506747B1

Reaction notes

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