Cesium carbonate → 1-(2-Methoxyethyl)-1H-pyrazole-4-boronic acid, pinacol ester

HRID 2090444Notes

Reaction equation

HRID 2090444 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.[CH3:15][O:16][CH2:17][CH2:18]Br.C(=O)([O-])[O-].[Cs+].[Cs+]>C(#N)C>[CH3:15][O:16][CH2:17][CH2:18][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

Participants

5

Reactant 3

HCID 10796Cesium carbonateHCID 809722-Bromoethyl methyl etherHCID 27740104-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole

Product 1

HCID 112304911-(2-Methoxyethyl)-1H-pyrazole-4-boronic acid, pinacol ester

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

A mixture of [A] 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (100 mg, 0.5 mmol), 2-bromoethyl methyl ether (58 uL, 0.62 mmol, Aldrich, Cat. No. 238155), and cesium carbonate (500.0 mg, 1.5 mmol) in acetonitrile (1 mL) was stirred at 90° C. overnight. After cooling it was quenched with water, extracted with ethyl acetate. The extract was washed with water twice, brine once; dried over Na2SO4. After filtration the filtrate was concentrated to yield 90 mg of the product. LCMS (M+H)+: m/z=253.1

Workup

  1. temperatureAfter cooling it
  2. customwas quenched with water
  3. extractionextracted 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-5d38d8c8493940958814448e6a3bd9f1
Source dataset
uspto-grants-2013_05
Patent number
US08436008B2

Reaction notes

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