Isoamyl Nitrite → ethyl 1-[4-(trifluoromethoxy)phenyl]-1H-pyrazole-4-carboxylate

HRID 1496928Notes

Reaction equation

HRID 1496928 reaction equation
N[C:2]1[N:6]([C:7]2[CH:12]=[CH:11][C:10]([O:13][C:14]([F:17])([F:16])[F:15])=[CH:9][CH:8]=2)[N:5]=[CH:4][C:3]=1[C:18]([O:20][CH2:21][CH3:22])=[O:19].N(OCCC(C)C)=O>C1COCC1>[F:17][C:14]([F:15])([F:16])[O:13][C:10]1[CH:11]=[CH:12][C:7]([N:6]2[CH:2]=[C:3]([C:18]([O:20][CH2:21][CH3:22])=[O:19])[CH:4]=[N:5]2)=[CH:8][CH:9]=1

Participants

4

Reactant 2

HCID 8053Isoamyl Nitrite2×HCID 622933Ethyl 5-amino-1-(4-(trifluoromethoxy)phenyl)-1H-pyrazole-4-carboxylate

Product 1

HCID 44818853ethyl 1-[4-(trifluoromethoxy)phenyl]-1H-pyrazole-4-carboxylateYield 87%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

A solution of aminopyrazole 115 (1.850 g, 5.87 mmol) and isoamyl nitrite (0.83 mL, 6.18 mmol) in THF (20 mL) was refluxed for 14 h, then further isoamyl nitrite (0.83 mL, 6.18 mmol) was added and the solution was refluxed for 6 h. The solvent was removed under reduced pressure to give a solid, which was recrystallised (EtOH) to give ethyl 1-[4-(trifluoromethoxy)phenyl]-1H-pyrazole-4-carboxylate (116) (1.527 g, 87%) as white flakes: mp 114-116° C.; 1H NMR (CDCl3) δ 8.38 (d, J=0.5 Hz, 1H), 8.10 (s, 1H), 7.74 (d, J=9.1 Hz, 2H), 7.34 (d, J=9.1 Hz, 2H), 4.35 (q, J=7.1 Hz, 2H), 1.38 (t, J=7.1 Hz, 3H). APCI MS m/z 301 [M+H]+.

Workup

  1. temperaturethe solution was refluxed for 6 h
  2. customThe solvent was removed under reduced pressure
  3. customto give a solid, which
  4. customwas recrystallised (EtOH)

Sources & evidence

ORD record
ord-d917042c5c774907bcb1d318f0f09727
Source dataset
uspto-grants-2015_12
Patent number
US09198913B2

Reaction notes

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