2-Bromopropane → HCID 19576680, compound

HRID 546091Notes

Reaction equation

HRID 546091 reaction equation
[N+:1]([C:4]1[CH:8]=[CH:7][NH:6][N:5]=1)([O-:3])=[O:2].[H-].[Na+].Br[CH:12]([CH3:14])[CH3:13]>CN(C)C=O>[CH:12]([N:6]1[CH:7]=[CH:8][C:4]([N+:1]([O-:3])=[O:2])=[N:5]1)([CH3:14])[CH3:13]

Participants

5

Reactant 3

HCID 63582-BromopropaneHCID 24758Sodium hydrideHCID 178526745HCID 178526745, compound

Product 1

HCID 19576680HCID 19576680, compoundYield 43%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
0 °C

Procedure

3-Nitro-1H-pyrazole (prepared in example 3, 250 mg, 2.21 mmol) was dissolved in anhydrous N,N-dimethylformamide (5.5 mL) and a 60% dispersion of sodium hydride in mineral oil (97 mg, 2.43 mmol) was added while stirring under nitrogen. After the effervescence ceased and the reaction stirred for an additional 25 min, the reaction was chilled to 0° C. and 2-bromo-propane (324 mg, 2.64 mmol) was added. The reaction continued to stir under nitrogen at 0° C. for 20 min. The ice bath was removed and the reaction continued to stir at 25° C. for 16 h. The reaction was diluted with ethyl acetate (100 mL), washed with water (2×50 mL), saturated aqueous brine solution (2×20 mL), dried over magnesium sulfate and concentrated in vacuo to give an oil. Purification by ISCO flash column chromatography (Teledyne Isco RediSep Flash Column 40 g; 0% ethyl acetate/hexanes to 20% ethyl acetate/hexanes) afforded 1-isopropyl-3-nitro-1H-pyrazole (146 mg, 43%) as a white waxy solid: H1-NMR (400 MHz, CDCl3) δ 1.58 (6H, d, J=6.8 Hz), 4.59 (1H, septet, J=6.4 Hz), 6.88 (1H, d, J=2.8 Hz), 7.47 (1H, d, J=2.0 Hz).

Workup

  1. stirringthe reaction stirred for an additional 25 min
  2. stirringto stir under nitrogen at 0° C. for 20 min
  3. customThe ice bath was removed
  4. stirringto stir at 25° C. for 16 h
  5. additionThe reaction was diluted with ethyl acetate (100 mL)
  6. washwashed with water (2×50 mL), saturated aqueous brine solution (2×20 mL)
  7. dry with materialdried over magnesium sulfate
  8. concentrationconcentrated in vacuo
  9. customto give an oil
  10. customPurification by ISCO flash column chromatography (Teledyne Isco RediSep Flash Column 40 g; 0% ethyl acetate/hexanes to 20% ethyl acetate/hexanes)

Sources & evidence

ORD record
ord-11b8ab2ef1d74e209f446341bf2437d7
Source dataset
uspto-grants-2011_05
Patent number
US07935699B2

Reaction notes

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