Nitric Acid → 5-(2-methylpropyl)-4-nitro-1H-pyrazole-3-carboxylic Acid

HRID 1063806Notes

Reaction equation

HRID 1063806 reaction equation
[CH2:1]([C:5]1[NH:9][N:8]=[C:7]([C:10]([OH:12])=[O:11])[CH:6]=1)[CH:2]([CH3:4])[CH3:3].S(=O)(=O)(O)O.[N+:18]([O-])([OH:20])=[O:19]>>[CH2:1]([C:5]1[NH:9][N:8]=[C:7]([C:10]([OH:12])=[O:11])[C:6]=1[N+:18]([O-:20])=[O:19])[CH:2]([CH3:4])[CH3:3]

Participants

4

Reactant 3

HCID 944Nitric AcidHCID 1118Sulfuric AcidHCID 6541713-Isobutyl-1H-pyrazole-5-carboxylic acid

Product 1

HCID 109658515-(2-methylpropyl)-4-nitro-1H-pyrazole-3-carboxylic Acid

Conditions

Temperature
60 °C

Procedure

5-Isobutyl-1H-pyrazol-3-carboxylic acid (5 g, 29.7 mmol) was added portionwise to concentrated sulfuric acid (25 ml) at room temperature with stirring. The reaction mixture was then heated to 60° C. and concentrated nitric acid (70%, 5.15 ml) was added dropwise, keeping the temperature at 60° C. The reaction was then stirred at 60° C. for 3 hours, cooled to room temperature and poured onto 50 ml of ice with stirring. The resultant white precipitate was isolated by filtration, washed with water and dried under reduced pressure to give 5-isobutyl-4-nitro-1H-pyrazol-3-carboxylic acid (6.4 g) as a white solid. 1H NMR (400 MHz, DMSO-D6): δ=2.71-2.76 (2H, d), 1.88-2.00 (1H, m), 0.80-0.87 (6H, d) ppm. LRMS (thermospray): m/z [M+NH4]+ 231, [M−H]+ 212. LRMS (electrospray): m/z [M−H]+ 212, [2M−H]+ 425. Anal. Found C, 42.54; H, 5.18; N, 18.63. C8H11N3O4. 0.7 mol H2O requires C, 42.55; H, 5.54; N, 18.61%.

Workup

  1. customat 60° C
  2. stirringThe reaction was then stirred at 60° C. for 3 hours
  3. temperaturecooled to room temperature
  4. stirringwith stirring
  5. customThe resultant white precipitate was isolated by filtration
  6. washwashed with water
  7. customdried under reduced pressure

Sources & evidence

ORD record
ord-6ebcef0ea82949d98f25b3a79ecc2421
Source dataset
uspto-grants-2005_11
Patent number
US06967204B2

Reaction notes

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