p-Toluenesulfonic acid monohydrate → 5-(5,5-Dimethylcyclopenten-1-yl)-1-methylpyrazole

HRID 337878Notes

Reaction equation

HRID 337878 reaction equation
[CH3:1][C:2]1([CH3:14])[CH2:6][CH2:5][CH2:4][C:3]1([C:8]1[N:12]([CH3:13])[N:11]=[CH:10][CH:9]=1)O.O.C1(C)C=CC(S(O)(=O)=O)=CC=1>C1(C)C=CC=CC=1>[CH3:1][C:2]1([CH3:14])[C:3]([C:8]2[N:12]([CH3:13])[N:11]=[CH:10][CH:9]=2)=[CH:4][CH2:5][CH2:6]1

Participants

4

Reactant 2

HCID 521998p-Toluenesulfonic acid monohydrateHCID 798630382,2-dimethyl-1-(1-methyl-1H-pyrazol-5-yl)Cyclopentanol

Product 1

HCID 899626145-(5,5-Dimethylcyclopenten-1-yl)-1-methylpyrazoleYield 90%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

A solution of the 2,2-dimethyl-1-(1-methyl-1H-pyrazol-5-yl)cyclopentanol (630 mg, 3.24 mmol) prepared in Example 99a and p-toluenesulfonic acid hydrate (2.00 g, 10.5 mmol) in toluene (20 mL) was stirred for 8 hours under reflux, and the solvent was subjected to azeotropic distillation with water. After allowing to cool, water (50 mL) was added to the reaction solution, and an organic layer was extracted. The thus obtained organic layer was dried over anhydrous sodium sulfate. After vacuum concentration, the residue was purified with silica gel chromatography (hexane/ethyl acetate=3:1) to yield the title compound (512 mg, 90%) as a brown oil.

Workup

  1. temperatureunder reflux
  2. distillationthe solvent was subjected to azeotropic distillation with water
  3. temperatureto cool
  4. additionwater (50 mL) was added to the reaction solution
  5. extractionan organic layer was extracted
  6. dry with materialThe thus obtained organic layer was dried over anhydrous sodium sulfate
  7. concentrationAfter vacuum concentration
  8. customthe residue was purified with silica gel chromatography (hexane/ethyl acetate=3:1)

Sources & evidence

ORD record
ord-d54c18a528a444a9b423b3f67431c7d4
Source dataset
uspto-grants-2014_11
Patent number
US08889741B2

Reaction notes

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