tert-Butanol → 4-nitro-1-phenyl-1H-Pyrazol-3-amine

HRID 733118Notes

Reaction equation

HRID 733118 reaction equation
[N+:1]([C:4]1[C:5](C(O)=O)=[N:6][N:7]([C:9]2[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=2)[CH:8]=1)([O-:3])=[O:2].C1(P([N:32]=[N+]=[N-])(C2C=CC=CC=2)=O)C=CC=CC=1.C(N(CC)CC)C.CC(O)(C)C>O1CCOCC1.C(OCC)(=O)C>[NH2:32][C:5]1[C:4]([N+:1]([O-:3])=[O:2])=[CH:8][N:7]([C:9]2[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=2)[N:6]=1

Participants

7

Reactant 4

HCID 6386tert-ButanolHCID 8471TriethylamineHCID 199401P,P-Diphenylphosphinic azideHCID 230849354-Nitro-1-phenyl-1H-pyrazole-3-carboxylic acid

Product 1

HCID 230849134-nitro-1-phenyl-1H-Pyrazol-3-amineYield 94.4%

Reagents, catalysts & solvents 2

HCID 8857Ethyl AcetateSolventHCID 312751,4-DioxaneSolvent

Procedure

To a solution of 4-nitro-1-phenyl-1H-pyrazole-3-carboxylic acid (1.00 g, 4.29 mmol) in 1,4-dioxane (15 mL) were added diphenylphosphoryl azide (1.44 mL, 6.65 mmol), triethylamine (1.79 mL, 12.9 mmol) and 2-methyl-2-propanol (7.2 mL, 75.3 mmol), and the mixture was heated under reflux for 2 hours under a nitrogen atmosphere. The reaction solution was cooled down to room temperature, and ethyl acetate was added thereto. The mixture was washed successively with water, saturated aqueous sodium bicarbonate solution and saturated brine, dried over anhydrous magnesium sulfate and concentrated in vacuo. The resulting residue was dissolved in chloroform (10 mL), and then trifluoroacetic acid (5 mL) was added thereto. The solution was stirred at room temperature for 1 hour under a nitrogen atmosphere. After the reaction solution was concentrated, ethyl acetate was added to the resulting residue. The solution was washed with saturated aqueous sodium bicarbonate solution and saturated aqueous brine, dried over anhydrous magnesium sulfate, and concentrated in vacuo. Diisopropyl ether was added to the resulting residue, and the precipitates were collected by filtration and dried to obtain the title compound (827 mg, 94%).

Workup

  1. temperaturethe mixture was heated
  2. temperatureunder reflux for 2 hours under a nitrogen atmosphere
  3. washThe mixture was washed successively with water, saturated aqueous sodium bicarbonate solution and saturated brine
  4. dry with materialdried over anhydrous magnesium sulfate
  5. concentrationconcentrated in vacuo
  6. dissolutionThe resulting residue was dissolved in chloroform (10 mL)
  7. additiontrifluoroacetic acid (5 mL) was added
  8. concentrationAfter the reaction solution was concentrated
  9. additionethyl acetate was added to the resulting residue
  10. washThe solution was washed with saturated aqueous sodium bicarbonate solution and saturated aqueous brine
  11. dry with materialdried over anhydrous magnesium sulfate
  12. concentrationconcentrated in vacuo
  13. additionDiisopropyl ether was added to the resulting residue
  14. filtrationthe precipitates were collected by filtration
  15. customdried

Sources & evidence

ORD record
ord-82d3060342144a999dc01fa5b288371b
Source dataset
uspto-grants-2009_09
Patent number
US07589096B2

Reaction notes

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