Sulfuric acid hydrate (1:1) → HCID 67189887, compound

HRID 546076Notes

Reaction equation

HRID 546076 reaction equation
[CH3:1][C:2]([CH3:13])=[CH:3][CH2:4][N:5]1[CH:9]=[CH:8][C:7]([N+:10]([O-:12])=[O:11])=[N:6]1.S(=O)(=O)(O)[OH:15].O>O1CCOCC1.O>[CH3:1][C:2]([OH:15])([CH2:3][CH2:4][N:5]1[CH:9]=[CH:8][C:7]([N+:10]([O-:12])=[O:11])=[N:6]1)[CH3:13]

Participants

5

Reactant 2

HCID 21910475Sulfuric acid hydrate (1:1)HCID 53256559HCID 53256559, compound

Product 1

HCID 67189887HCID 67189887, compoundYield 43%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 312751,4-DioxaneSolvent

Conditions

Temperature
85 °C

Procedure

1-(3-Methyl-but-2-enyl)-3-nitro-1H-pyrazole (1.29 g, 7.13 mmol) was dissolved in dioxane (30 mL). While stirring, a solution containing 50% concentrated sulfuric acid/water (3 mL) was added dropwise. The reaction was heated to 85° C. while stirring for 12 h. The reaction was diluted with water (50 mL) and the product extracted into ethyl acetate (3×60 mL). The combined organic layers were dried over magnesium sulfate and concentrated in vacuo to an oil. Purification by flash column chromatography (Merck silica gel 60, 40-63 μm; 15% ethyl acetate/hexanes to 100% ethyl acetate/hexanes) afforded 2-methyl-4-(3-nitro-pyrazol-1-yl)-butan-2-ol (608 mg, 43%) as a thick golden oil: H1-NMR (400 MHz, CDCl3) δ 1.30 (6H, s), 1.54 (1H, bs), 2.11-2.15 (2H, m), 4.36-4.39 (2H, m), 6.87 (1H, d, J=2.8 Hz), 7.48 (1H, d, J=2.8 Hz).

Workup

  1. additionwas added dropwise
  2. stirringwhile stirring for 12 h
  3. extractionthe product extracted into ethyl acetate (3×60 mL)
  4. dry with materialThe combined organic layers were dried over magnesium sulfate
  5. concentrationconcentrated in vacuo to an oil
  6. customPurification by flash column chromatography (Merck silica gel 60, 40-63 μm; 15% ethyl acetate/hexanes to 100% ethyl acetate/hexanes)

Sources & evidence

ORD record
ord-1848c3ee766b498b90b12182a75342eb
Source dataset
uspto-grants-2011_05
Patent number
US07935699B2

Reaction notes

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