Dimethylformamide → (R)-2,2-dimethyl-4-(3-nitro-pyrazol-1-ylmethyl)-oxazolidine-3-carboxylic acid t-butyl ester

HRID 19194Notes

Reaction equation

[C:1]([O:5][C:6]([N:8]1[CH2:12][CH2:11][O:10][CH:9]1[CH2:13]OS(C1C=CC(C)=CC=1)(=O)=O)=[O:7])([CH3:4])([CH3:3])[CH3:2].[C:25](=O)([O-])[O-].[K+].[K+].[N+:31]([C:34]1[CH:38]=CN[N:35]=1)([O-:33])=[O:32].[CH3:39][N:40]([CH3:43])C=O>C(OCC)(=O)C>[C:1]([O:5][C:6]([N:8]1[C@H:12]([CH2:39][N:40]2[CH:43]=[CH:38][C:34]([N+:31]([O-:33])=[O:32])=[N:35]2)[CH2:11][O:10][C:9]1([CH3:13])[CH3:25])=[O:7])([CH3:2])([CH3:3])[CH3:4]

Participants

Conditions

Temperature: 60 °C

Procedure

To a stirred mixture of (S)-2,2-dimethyl-4-(toluene-4-sulfonyloxymethyl-oxazolidine-3-carboxylic acid t-butyl ester (2.20 g, 5.71 mmol) in N,N-dimethylformamide (10 mL) was added potassium carbonate (0.93 g, 6.73 mmol) and 3-nitro-1H-pyrazole (prepared as in Example 5, 0.59 mg, 5.20 mmol). After addition was complete the mixture was stirred at 60° C. for 18 h. The reaction mixture was diluted with ethyl acetate, washed with water followed by a saturated sodium chloride solution and dried over magnesium sulfate. The organic layer was concentrated, and the crude product was purified by ISCO flash chromatography (Teledyne Isco RediSep Flash Column 40 g; 0% to 100% ethyl acetate/hexanes) to afford (R)-2,2-dimethyl-4-(3-nitro-pyrazol-1-ylmethyl)-oxazolidine-3-carboxylic acid t-butyl ester (1.21 g, 65%) as a colorless oil: LR-ES-MS m/z calculated for C14H22N4O5 [M]+ 326, observed 327 [M+H]+.

Workup

additionAfter addition
washwashed with water
dry with materialdried over magnesium sulfate
concentrationThe organic layer was concentrated
customthe crude product was purified by ISCO flash chromatography (Teledyne Isco RediSep Flash Column 40 g; 0% to 100% ethyl acetate/hexanes)

Sources & evidence

ORD record: ord-35d5750b182c46519ed7608834d5ac46
Source dataset: uspto-grants-2010_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07741327B2

Reaction notes

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