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

HRID 1930350Notes

Reaction equation

HRID 1930350 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 cone. 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-fd29924a79194e8ebb48a5bbb2ec645f
Source dataset
uspto-grants-2012_05
Patent number
US08188113B2

Reaction notes

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