Pentanenitrile, 4,4-dimethyl-3-oxo- → 3-Tert-butyl-1-(2,4-dimethylphenyl)-1H-pyrazol-5-amine

HRID 631609Notes

Reaction equation

HRID 631609 reaction equation
Cl.[CH3:2][C:3]1[CH:8]=[C:7]([CH3:9])[CH:6]=[CH:5][C:4]=1[NH:10][NH2:11].[CH3:12][C:13]([CH3:20])([CH3:19])[C:14](=O)[CH2:15][C:16]#[N:17]>CCO.O>[C:13]([C:14]1[CH:15]=[C:16]([NH2:17])[N:10]([C:4]2[CH:5]=[CH:6][C:7]([CH3:9])=[CH:8][C:3]=2[CH3:2])[N:11]=1)([CH3:20])([CH3:19])[CH3:12]

Participants

4

Reactant 2

HCID 108871Pentanenitrile, 4,4-dimethyl-3-oxo-HCID 162130592,4-Dimethylphenylhydrazine hydrochloride

Product 1

HCID 167700803-Tert-butyl-1-(2,4-dimethylphenyl)-1H-pyrazol-5-amineYield 36%

Reagents, catalysts & solvents 1

HCID 19096565Water ethanolSolvent

Procedure

To a heated solution of 2,4-dimethylphenylhydrazine hydrochloride (1.38 g, 8 mmol) in EtOH/water/1M NaOH (20 mL/12 mL/8 mL) at 50° C., 4,4-dimethyl-3-oxopentanenitrile (1.0 g, 8 mmol) was added and the reaction heated until finished by LC-MS. The solution was partitioned between EtOAc and water, and extracted twice. The extracts were washed with brine, dried with magnesium sulfate, filtered, and concentrated. Purification using silica gel chromatography eluting with an EtOAC/hexane gradient (5-20%) gave 3-tert-butyl-1-(2,4-dimethylphenyl)-1H-pyrazol-5-amine (700 mg, 36% yield). 1H NMR (300 MHz, DMSO d6) δ 1.09 (s, 9H), 1.98 (s, 3H), 2.32 (s, 3H), 4.76 (s, 2H), 5.26 (s, 1H), 7.11 (m, 3H). LC-MS (ESI) m/z 244 (M+H)+.

Workup

  1. temperaturethe reaction heated
  2. customThe solution was partitioned between EtOAc and water
  3. extractionextracted twice
  4. washThe extracts were washed with brine
  5. dry with materialdried with magnesium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated
  8. customPurification
  9. washeluting with an EtOAC/hexane gradient (5-20%)

Sources & evidence

ORD record
ord-9241d14623984e6e9bd088561734abcc
Source dataset
uspto-grants-2016_04
Patent number
US09320739B2

Reaction notes

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