Trimethyl borate → [2,6-Dimethoxy-4-(1-methoxyethyl)phenyl]boronic acid

HRID 41250Notes

Reaction equation

HRID 41250 reaction equation
Br[C:2]1[C:7]([O:8][CH3:9])=[CH:6][C:5]([CH:10]([O:12][CH3:13])[CH3:11])=[CH:4][C:3]=1[O:14][CH3:15].C([Li])CCC.[B:21](OC)([O:24]C)[O:22]C.[Cl-].[NH4+]>O1CCCC1>[CH3:15][O:14][C:3]1[CH:4]=[C:5]([CH:10]([O:12][CH3:13])[CH3:11])[CH:6]=[C:7]([O:8][CH3:9])[C:2]=1[B:21]([OH:24])[OH:22]

Participants

6

Reactant 4

HCID 8470Trimethyl borateHCID 25517Ammonium ChlorideHCID 582234192-Bromo-1,3-dimethoxy-5-(1-methoxyethyl)benzeneHCID 178418339Butyllithium

Product 1

HCID 58223453[2,6-Dimethoxy-4-(1-methoxyethyl)phenyl]boronic acidYield 77%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a tetrahydrofuran (200 ml) solution of 2-bromo-1,3-dimethoxy-5-(1-methoxyethyl)benzene (7.39 g, 26.9 mmol), was added dropwise 1.57M n-butyl lithium (18.8 ml, 29.6 mmol) at −78° C., and the mixture was stirred for 30 minutes. To the mixture, was added dropwise trimethyl borate (6.00 ml, 53.8 mmol), and warmed to room temperature. After the reaction was completed, a saturated aqueous solution of ammonium chloride was added while cooling on ice, which was extracted with ethyl acetate and dried over anhydrous magnesium sulfate, and the solvent was then distilled off under reduced pressure. The residue was purified by silica gel column chromatography (n-heptane/ethyl acetate=1/1) to obtain the title compound (4.97 g, 20.7 mmol)

Workup

  1. temperaturewhile cooling on ice, which
  2. extractionwas extracted with ethyl acetate
  3. dry with materialdried over anhydrous magnesium sulfate
  4. distillationthe solvent was then distilled off under reduced pressure
  5. customThe residue was purified by silica gel column chromatography (n-heptane/ethyl acetate=1/1)

Sources & evidence

ORD record
ord-63ab5f25dd144985a5ddcef1d408e7c9
Source dataset
uspto-grants-2013_09
Patent number
US08530504B2

Reaction notes

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