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

HRID 599319Notes

Reaction equation

HRID 599319 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 pre-HPLC to provide 2-methyl-5-trifluoromethyl-2H-pyrazol-3-ylamine (2.07 g, 21% yield). 1HNMR (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 pre-HPLC

Sources & evidence

ORD record
ord-67908363196245699605c2f0cfb3fdf1
Source dataset
uspto-grants-2011_03
Patent number
US07897762B2

Reaction notes

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