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

HRID 902205Notes

Reaction equation

HRID 902205 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 solutionwas washedwith saturatedaqueous sodiumbicarbonate 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. dry with materialThe solutionwas washedwith saturatedaqueous sodiumbicarbonate solution and saturated aqueous brine, dried over anhydrous magnesium sulfate
  11. concentrationconcentrated in vacuo
  12. additionDiisopropyl ether was added to the resulting residue
  13. filtrationthe precipitates were collected by filtration
  14. customdried

Sources & evidence

ORD record
ord-d1148f57bc9946d5a82f9056026be39f
Source dataset
uspto-grants-2008_04
Patent number
US07365079B2

Reaction notes

Loading…