Iodoethane → 1-Ethyl-1H-pyrazole-4-boronic acid, pinacol ester

HRID 2090432Notes

Reaction equation

HRID 2090432 reaction equation
[CH3:1][C:2]1([CH3:14])[C:6]([CH3:8])([CH3:7])[O:5][B:4]([C:9]2[CH:10]=[N:11][NH:12][CH:13]=2)[O:3]1.I[CH2:16][CH3:17].C(=O)([O-])[O-].[Cs+].[Cs+]>C(#N)C>[CH2:16]([N:12]1[CH:13]=[C:9]([B:4]2[O:5][C:6]([CH3:7])([CH3:8])[C:2]([CH3:14])([CH3:1])[O:3]2)[CH:10]=[N:11]1)[CH3:17]

Participants

5

Reactant 3

HCID 6340IodoethaneHCID 10796Cesium carbonateHCID 27740104-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole

Product 1

HCID 113790451-Ethyl-1H-pyrazole-4-boronic acid, pinacol ester

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

A mixture of 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (0.05 g, 0.2 mmol), iodoethane (31 uL, 0.39 mmol, Sigma-Aldrich, Cat. No. 17780), and cesium carbonate (250 mg, 0.77 mmol) in acetonitrile (1 mL) was stirred at 90° C. for 2 h. After cooling it was quenched with water. The product was extracted with ethyl acetate. The extract was washed with water twice, brine once; dried over Na2SO4. After filtration the filtrate was concentrated to yield 34 mg of the product which was directly used in the next step reaction without further purification.

Workup

  1. temperatureAfter cooling it
  2. customwas quenched with water
  3. extractionThe product was extracted with ethyl acetate
  4. washThe extract was washed with water twice
  5. dry with materialdried over Na2SO4
  6. filtrationAfter filtration the filtrate
  7. concentrationwas concentrated

Sources & evidence

ORD record
ord-8bf2e645631b44b2a71f471b279dad3f
Source dataset
uspto-grants-2013_05
Patent number
US08436008B2

Reaction notes

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