Hydrochloric Acid → 1-methyl-3-(trifluoromethyl)-1H-pyrazol-5-amine

HRID 1098569Notes

Reaction equation

HRID 1098569 reaction equation
[CH3:1][NH:2][NH2:3].[F:4][C:5]([F:12])([F:11])[C:6](=O)[CH2:7][C:8]#[N:9].Cl>CCO>[CH3:1][N:2]1[C:8]([NH2:9])=[CH:7][C:6]([C:5]([F:12])([F:11])[F:4])=[N:3]1

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 6061MethylhydrazineHCID 138435404,4,4-Trifluoro-3-oxobutanenitrile

Product 1

HCID 196233031-methyl-3-(trifluoromethyl)-1H-pyrazol-5-amineYield 21%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A solution of methylhydrazine (5.0 g, 60 mmol) and 4,4,4-trifluoro-3-oxo-butyronitrile (9.8 g, 71 mmol) in EtOH (50 mL) was treated with conc. HCl (5 mL) and the resultant mixture was heated to reflux overnight. The solvent was removed in vacuo and the crude product was dissolved in EtOAc washed with saturated aq. Na2CO3 solution until the washings were pH 8. The organics were concentrated and purified by prep-HPLC to provide 2-methyl-5-trifluoromethyl-2H-pyrazol-3-ylamine (2.07 g, 21% yield). 1H NMR (300 MHz, DMSO-d6), δ 5.57 (s, 1 H), 5.54 (br s, 2 H), 3.55 (s, 3 H); MS (ESI) m/z: 166.1 (M+H+).

Workup

  1. temperatureto reflux overnight
  2. customThe solvent was removed in vacuo
  3. dissolutionthe crude product was dissolved in EtOAc
  4. washwashed with saturated aq. Na2CO3 solution until the washings
  5. concentrationThe organics were concentrated
  6. custompurified by prep-HPLC

Sources & evidence

ORD record
ord-4c3c327c0ab04c749843ef49eaf5136a
Source dataset
uspto-grants-2012_03
Patent number
US08143293B2

Reaction notes

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