Trimethyl borate → (3,5-Dimethoxyphenyl)boronic acid

HRID 43049Notes

Reaction equation

HRID 43049 reaction equation
[Li]C(C)(C)C.[CH3:6][O:7][C:8]1[CH:9]=[C:10](Br)[CH:11]=[C:12]([O:14][CH3:15])[CH:13]=1.[B:17](OC)([O:20]C)[O:18]C>C1COCC1>[CH3:6][O:7][C:8]1[CH:9]=[C:10]([B:17]([OH:20])[OH:18])[CH:11]=[C:12]([O:14][CH3:15])[CH:13]=1

Participants

5

Reactant 3

HCID 8470Trimethyl borateHCID 6391871-Bromo-3,5-dimethoxybenzeneHCID 178418306HCID 178418306, compound

Product 1

HCID 4374257(3,5-Dimethoxyphenyl)boronic acidYield 73.7%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
-78 °C

Procedure

t-BuLi (1.7 M in pentatne, 63 mL, 106 mmol, 2.1 equiv) was added dropwise to a cold (−78° C.) solution of 3,5-dimethoxy-bromobenzene (11 g, 50.7 mmol) in THF (400 mL), under an argon atmosphere. The yellow mixture si stirred for 45 min at −78° C. Trimethyl borate (20 mL, 179 mmol, 3.5 equiv) was then added. The colorless reaction mixture was allowed to warm to 0° C., quenched by addition of a saturated solution of NH4Cl (5 mL), and concentrated. The residue was diluted with EtOAc/NH4Cl (saturated aqueous solution), and extracted with EtOAc. The organic phase was dried (Na2SO4), filtered and concentrated. The residue was triturated in Et2O to provide 6.8 g of the title compound as a white solid: ESI-MS: 183.1 [M+H]+; tR=2.70 min (System 1).

Workup

  1. temperatureto warm to 0° C.
  2. customquenched by addition of a saturated solution of NH4Cl (5 mL)
  3. concentrationconcentrated
  4. additionThe residue was diluted with EtOAc/NH4Cl (saturated aqueous solution)
  5. extractionextracted with EtOAc
  6. dry with materialThe organic phase was dried (Na2SO4)
  7. filtrationfiltered
  8. concentrationconcentrated
  9. customThe residue was triturated in Et2O

Sources & evidence

ORD record
ord-61ad4bcb3c7a4f99aa2cbcd1691366af
Source dataset
uspto-grants-2013_09
Patent number
US08536175B2

Reaction notes

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