Phenylhydrazine → 1-phenyl-3-(trifluoromethyl)-1H-pyrazol-5-amine

HRID 1917915Notes

Reaction equation

HRID 1917915 reaction equation
[NH2:1]/[C:2](/OCC)=[CH:3]\[C:4](=O)[C:5]([F:8])([F:7])[F:6].[C:13]1([NH:19][NH2:20])[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1>CCO>[C:13]1([N:19]2[C:2]([NH2:1])=[CH:3][C:4]([C:5]([F:6])([F:7])[F:8])=[N:20]2)[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1

Participants

4

Reactant 2

HCID 7516PhenylhydrazineHCID 151117544-Amino-4-ethoxy-1,1,1-trifluorobut-3-en-2-one

Product 1

HCID 431589511-phenyl-3-(trifluoromethyl)-1H-pyrazol-5-amineYield 66%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Conditions

Temperature
95 °C

Procedure

A mixture of (E)-4-amino-4-ethoxy-1,1,1-trifluorobut-3-en-2-one (2.93 g, 16 mmol) and phenylhydrazine (1.947 g, 18 mmol) in EtOH (15 mL) was heated at 95° C. for 8 hours. The reaction was quenched with water and extracted with CH2Cl2. Extracts were dried over MgSO4 and concentrated under reduced pressure. The crude product was purified by silica gel chromatography with 5-25% EtOAc/hexane as eluants to afford 1-phenyl-3-(trifluoromethyl)-1H-pyrazol-5-amine as a yellow solid (2.23 g, 66%). 1H NMR (300 MHz, CDCl3) δ 7.51 (m, 5H), 5.87 (s, 1H), 3.93 (br, 2H); LC-MS (ESI) m/z 228 (M+H)+.

Workup

  1. customThe reaction was quenched with water
  2. extractionextracted with CH2Cl2
  3. dry with materialExtracts were dried over MgSO4
  4. concentrationconcentrated under reduced pressure
  5. customThe crude product was purified by silica gel chromatography with 5-25% EtOAc/hexane as eluants

Sources & evidence

ORD record
ord-86d5556cfb784f4aa79be7ba3964e22e
Source dataset
uspto-grants-2013_12
Patent number
US08618289B2

Reaction notes

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