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

HRID 18984Notes

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

Conditions

Temperature: 90 °C

Procedure

A solution of 3-nitro-1H-pyrazole (prepared as in Example 5, 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-yl-methyl 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. Purification by ISCO flash chromatography (128 g, 5-30% ethyl acetate/hexanes) afforded 1-((R)-2,2-dimethyl-[1,3]dioxolan-4-yl-methyl)-3-nitro-1H-pyrazole (14.5 g, 73%) as a light yellow oil.

Workup

washwashed with water
dry with materiala saturated aqueous sodium chloride solution, dried over sodium sulfate
filtrationfiltered
washrinsed
concentrationconcentrated in vacuo
customPurification by ISCO flash chromatography (128 g, 5-30% ethyl acetate/hexanes)

Sources & evidence

ORD record: ord-d55ee2388b804569afd119b61a3be8bb
Source dataset: uspto-grants-2010_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07741327B2

Reaction notes

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