2,2-Dimethoxypropane → 1-((S)-2,2-dimethyl-[1,3]dioxolan-4-ylmethyl)-3-nitro-1H-pyrazole

HRID 19191Notes

Reaction equation

HRID 19191 reaction equation
[N+:1]([C:4]1[CH:8]=[CH:7][N:6]([CH2:9][C@H:10]([OH:13])[CH2:11][OH:12])[N:5]=1)([O-:3])=[O:2].CO[C:16](OC)([CH3:18])[CH3:17]>CC(C)=O.S(=O)(=O)(O)O>[CH3:17][C:16]1([CH3:18])[O:13][C@@H:10]([CH2:9][N:6]2[CH:7]=[CH:8][C:4]([N+:1]([O-:3])=[O:2])=[N:5]2)[CH2:11][O:12]1

Participants

5

Reactant 2

HCID 64952,2-DimethoxypropaneHCID 59344949(S)-3-(3-nitro-1h-pyrazol-1-yl)propane-1,2-diol

Product 1

HCID 593449571-((S)-2,2-dimethyl-[1,3]dioxolan-4-ylmethyl)-3-nitro-1H-pyrazoleYield 58%

Reagents, catalysts & solvents 2

HCID 1118Sulfuric AcidCatalystHCID 180AcetoneSolvent

Procedure

A solution of (S)-3-(3-nitro-pyrazol-1-yl)propane-1,2-diol (1.00 g, 5.35 mmol) in acetone (10 mL) was treated with concentrated sulfuric acid (5 drops) and 2,2-dimethoxypropane (3.34 g, 32.09 mmol). The reaction mixture was stirred for 5 h at room temperature. Upon completion of the reaction the mixture was concentrated at reduced pressure and then diluted with ethyl acetate, washed with a saturated sodium bicarbonate solution, a saturated sodium chloride solution and dried over magnesium sulfate The crude product obtained was purified by ISCO flash chromatography (Teledyne Isco RediSep Flash Column 40 g; 0% to 80% ethyl acetate/hexanes) to afford 1-((S)-2,2-dimethyl-[1,3]dioxolan-4-yl-methyl)-3-nitro-1H-pyrazole (0.70 g, 58%) as a yellow oil: LR-ES-MS m/z calculated for C9H13N3O4 [M]+ 227, observed 228 [M+H]+.

Workup

  1. customUpon completion of the reaction the mixture
  2. concentrationwas concentrated at reduced pressure
  3. additiondiluted with ethyl acetate
  4. washwashed with a saturated sodium bicarbonate solution
  5. dry with materiala saturated sodium chloride solution and dried over magnesium sulfate The crude product
  6. customobtained
  7. customwas purified by ISCO flash chromatography (Teledyne Isco RediSep Flash Column 40 g; 0% to 80% ethyl acetate/hexanes)

Sources & evidence

ORD record
ord-165d2726afc645c9bc54f13da61ed780
Source dataset
uspto-grants-2010_06
Patent number
US07741327B2

Reaction notes

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