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

HRID 871683Notes

Reaction equation

HRID 871683 reaction equation
[F:1][C:2]([F:12])([C:8]([F:11])([F:10])[F:9])[C:3](=O)[CH2:4][C:5]#[N:6].Cl.[C:14]1([NH:20][NH2:21])[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1>C(O)C>[F:1][C:2]([F:12])([C:3]1[CH:4]=[C:5]([NH2:6])[N:20]([C:14]2[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=2)[N:21]=1)[C:8]([F:9])([F:11])[F:10]

Participants

4

Reactant 2

HCID 60962Phenylhydrazine hydrochlorideHCID 156138214,4,5,5,5-Pentafluoro-3-oxopentanenitrile

Product 1

HCID 866535313-(perfluoroethyl)-1-phenyl-1H-pyrazol-5-amineYield 43.4%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Conditions

Temperature
90 °C

Procedure

A stirred mixture of 4,4,5,5,5-pentafluoro-3-oxopentanenitrile (500 mg, 2.66 mmol) and phenylhydrazine hydrochloride (386 mg, 2.66 mmol) in ethanol (5 mL) was heated at 90° C. for 4 h. The reaction mixture was concentrated under reduced pressure, and the obtained oil purified by silica gel flash column chromatography (eluting with a gradient of 100% petroleum ether to 10% ethyl acetate in petroleum ether) to afford 3-(perfluoroethyl)-1-phenyl-1H-pyrazol-5-amine (320 mg, 43%) as a solid. 1H NMR (400 MHz, CDCl3) δ 7.51-7.60 (m, 4H), 7.45 (m, 1H), 5.91 (s, 1H), 3.96 (brs, 2H); LC-MS (ESI) m/z 278 (M+H)+.

Workup

  1. concentrationThe reaction mixture was concentrated under reduced pressure
  2. customthe obtained oil purified by silica gel flash column chromatography (
  3. washeluting with a gradient of 100% petroleum ether to 10% ethyl acetate in petroleum ether)

Sources & evidence

ORD record
ord-0195a3075e304bfcb7f7fc9048c22b12
Source dataset
uspto-grants-2015_03
Patent number
US08969587B2

Reaction notes

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