Potassium Carbonate → 1-((R)-2,2-dimethyl-[1,3]dioxolan-4-ylmethyl)-3-nitro-1H-pyrazole

HRID 2381282Notes

Reaction equation

HRID 2381282 reaction equation
[N+:1]([C:4]1[CH:8]=[CH:7][NH:6][N:5]=1)([O-:3])=[O:2].[CH3:9][C:10]1([CH3:27])[O:14][C@H:13]([CH2:15]OS(C2C=CC(C)=CC=2)(=O)=O)[CH2:12][O:11]1.C(=O)([O-])[O-].[K+].[K+]>CN(C)C=O.C(OCC)(=O)C>[CH3:9][C:10]1([CH3:27])[O:14][C@H:13]([CH2:15][N:6]2[CH:7]=[CH:8][C:4]([N+:1]([O-:3])=[O:2])=[N:5]2)[CH2:12][O:11]1

Participants

6

Reactant 3

HCID 11430Potassium CarbonateHCID 2723760(S)-(+)-2,2-Dimethyl-1,3-dioxolan-4-ylmethyl p-ToluenesulfonateHCID 178526745HCID 178526745, compound2×

Product 1

HCID 593449371-((R)-2,2-dimethyl-[1,3]dioxolan-4-ylmethyl)-3-nitro-1H-pyrazoleYield 73%

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideSolventHCID 8857Ethyl AcetateSolvent

Conditions

Temperature
90 °C

Procedure

A solution of 3-nitro-1H-pyrazole (Intermediate 2, 12.0 g, 106 mmol) in N,N-dimethylformamide (150 mL) was treated with para-toluenesulfonic acid (S)-2,2-dimethyl-[1,3]dioxolan-4-ylmethyl ester (25.5 g, 89.0 mmol), and potassium carbonate (24.5 g, 178 mmol). The reaction mixture was heated to 90° C. for 6 h under nitrogen. After this time, the reaction mixture was diluted with ethyl acetate, washed with water and a saturated aqueous sodium chloride solution, dried over sodium sulfate, filtered, rinsed and concentrated in vacuo. Silica gel column chromatography (ISCO 120 g, 5-30% ethyl acetate/hexanes) afforded 1-((R)-2,2-dimethyl-[1,3]dioxolan-4-ylmethyl)-3-nitro-1H-pyrazole (14.5 g, 73%) as a light yellow oil; ESI-LRMS m/e calcd for C9H13N3O4 [M+H+] 228, found 228 [M+H+].

Workup

  1. washwashed with water
  2. dry with materiala saturated aqueous sodium chloride solution, dried over sodium sulfate
  3. filtrationfiltered
  4. washrinsed
  5. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-18304ccf281c431a8e3e3ddf2aed9116
Source dataset
uspto-grants-2012_09
Patent number
US08258134B2

Reaction notes

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