Dimethylformamide → 1H-Pyrazole-3-carboxamide, 5-(1-methylethyl)-4-nitro-

HRID 1063793Notes

Reaction equation

HRID 1063793 reaction equation
C(Cl)(=O)C(Cl)=O.[CH:7]([C:10]1[NH:14][N:13]=[C:12]([C:15](O)=[O:16])[C:11]=1[N+:18]([O-:20])=[O:19])([CH3:9])[CH3:8].C[N:22](C)C=O>ClCCl>[CH:7]([C:10]1[NH:14][N:13]=[C:12]([C:15]([NH2:22])=[O:16])[C:11]=1[N+:18]([O-:20])=[O:19])([CH3:9])[CH3:8]

Participants

5

Reactant 3

HCID 6228DimethylformamideHCID 65578Oxalyl chlorideHCID 121506014-nitro-5-(propan-2-yl)-1H-pyrazole-3-carboxylic acid

Product 1

HCID 160997461H-Pyrazole-3-carboxamide, 5-(1-methylethyl)-4-nitro-

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Conditions

Temperature
0 °C

Procedure

Oxalyl chloride (6.8 ml, 77.6 mmol) was added dropwise to a suspension of 5-isopropyl-4-nitro-1H-pyrazol-3-carboxylic acid (5.15 g, 25.9 mmol) in dichloromethane (80 ml) containing dimethylformamide (0.1 ml) under nitrogen at 0° C. The reaction was stirred at 0° C. for 1 hours, allowed to warm to room temperature and stirred for a further 2 hours. The solvent was removed under reduced pressure, the residue was dissolved in toluene (100 ml) and ammonia gas was bubbled into the solution for 2 hours. The reaction was stirred under nitrogen at room temperature for 18 hours, concentrated under reduced pressure and the residue was dissolved in hot methanol (300 ml). The resultant precipitate was filtered and the filtrate was concentrated under reduced pressure. The residue was azeotroped with water (300 ml), concentrated to approximately 80 ml under reduced pressure and the precipitate was isolated by filtration. This was washed with water and dried under to give 5-isopropyl-4-nitro-1H-pyrazol-3-carboxylic acid amide (3.1 g) as an orange solid. 1H NMR (400 MHz, DMSO-D6): δ=7.94-7.99 (1H, brs), 7.68-7.72 (1H, brs), 3.45-3.55 (1H, m), 1.24-1.30 (6H, d) ppm. LRMS (electrospray): m/z [M+Na]+ 221, [M−H]+ 197.

Workup

  1. temperatureto warm to room temperature
  2. stirringstirred for a further 2 hours
  3. customThe solvent was removed under reduced pressure
  4. dissolutionthe residue was dissolved in toluene (100 ml)
  5. customammonia gas was bubbled into the solution for 2 hours
  6. stirringThe reaction was stirred under nitrogen at room temperature for 18 hours
  7. concentrationconcentrated under reduced pressure
  8. dissolutionthe residue was dissolved in hot methanol (300 ml)
  9. filtrationThe resultant precipitate was filtered
  10. concentrationthe filtrate was concentrated under reduced pressure
  11. customThe residue was azeotroped with water (300 ml)
  12. concentrationconcentrated to approximately 80 ml under reduced pressure
  13. customthe precipitate was isolated by filtration
  14. washThis was washed with water
  15. customdried under

Sources & evidence

ORD record
ord-678f55d64bd14448b9557e09c7df193b
Source dataset
uspto-grants-2005_11
Patent number
US06967204B2

Reaction notes

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