Cesium carbonate → HCID 86710242, compound

HRID 2405933Notes

Reaction equation

[NH:1]1[CH:5]=[C:4]([C:6]2[CH:11]=[N:10][CH:9]=[CH:8][N:7]=2)[CH:3]=[N:2]1.C(=O)([O-])[O-].[Cs+].[Cs+].S([O-])([O-])(=O)=O.[Na+].[Na+].Br[CH2:26][CH2:27][C@@:28]([CH3:38])([S:34]([CH3:37])(=[O:36])=[O:35])[C:29]([O:31][CH2:32][CH3:33])=[O:30]>C(#N)C>[CH3:38][C@@:28]([S:34]([CH3:37])(=[O:35])=[O:36])([CH2:27][CH2:26][N:1]1[CH:5]=[C:4]([C:6]2[CH:11]=[N:10][CH:9]=[CH:8][N:7]=2)[CH:3]=[N:2]1)[C:29]([O:31][CH2:32][CH3:33])=[O:30]

Participants

Conditions

Temperature: 50 °C

Procedure

To a solution of 2-(1H-pyrazol-4-yl)pyrazine (0.157 g, 1.07 mmol) in acetonitrile (10 mL) was added cesium carbonate (0.873 g, 2.78 mmol, 2.5 eq), sodium sulfate (0.032 g, 0.214 mmol, 0.2 eq) and (R)-ethyl 4-bromo-2-methyl-2-(methylsulfonyl)butanoate (0.4 g 1.39 mmol, 1.3 eq). The mixture was heated at 50° C. overnight. The reaction mixture was filtered over a pad of diatomateous earth. The filtrate was evaporated in vacuo. The crude product was purified by flash chromatography on silica gel eluting with 40-100% ethyl acetate/heptane to give ethyl (2R)-2-methyl-2-(methylsulfonyl)-4-[4-(pyrazin-2-yl)-1H-pyrazol-1-yl]butanoate (0.320 g, 1.39 mmol, 65% yield). LC-MS M+H+353.2.

Workup

filtrationThe reaction mixture was filtered over a pad of diatomateous earth
customThe filtrate was evaporated in vacuo
customThe crude product was purified by flash chromatography on silica gel eluting with 40-100% ethyl acetate/heptane

Sources & evidence

ORD record: ord-06c04a59c5e6496693458d0d6292e2fc
Source dataset: uspto-grants-2014_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08809333B2

Reaction notes

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