Trimethyl borate → 4-Hexylphenylboronic Acid

HRID 1841915Notes

Reaction equation

HRID 1841915 reaction equation
Br[C:2]1[CH:7]=[CH:6][C:5]([CH2:8][CH2:9][CH2:10][CH2:11][CH2:12][CH3:13])=[CH:4][CH:3]=1.C([Li])(C)(C)C.[B:19](OC)([O:22]C)[O:20]C>C1COCC1>[CH2:8]([C:5]1[CH:6]=[CH:7][C:2]([B:19]([OH:22])[OH:20])=[CH:3][CH:4]=1)[CH2:9][CH2:10][CH2:11][CH2:12][CH3:13]

Participants

5

Reactant 3

HCID 8470Trimethyl borateHCID 5981861-Bromo-4-hexylbenzeneHCID 178418306HCID 178418306, compound

Product 1

HCID 41978644-Hexylphenylboronic AcidYield 118.5%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
-78 °C

Procedure

To a solution of 4-bromo-1-hexylbenzene (500 mg, 1.7 mmol) in THF (15 mL) at −78° C. was added t-butyllithium (1.7 M in pentane, 2.0 mL) slowly dropwise. After stirring at −78° C. for 1 h, trimethyl borate (0.39 mL, 3.46 mmol) was added. The reaction mixture was warmed at RT over 2 h. After stirring at RT for 15 min, the reaction mixture was quenched with saturated solution of ammonium chloride and extracted with ethyl acetate. The combined organic layers were washed with HCl (10% solution), brine, and dried (MgSO4), filtered, and concentrated under reduce pressure to give 415 mg (4-hexylphenyl)boronic acid as a colorless solid.

Workup

  1. temperatureThe reaction mixture was warmed at RT over 2 h
  2. stirringAfter stirring at RT for 15 min
  3. customthe reaction mixture was quenched with saturated solution of ammonium chloride
  4. extractionextracted with ethyl acetate
  5. washThe combined organic layers were washed with HCl (10% solution), brine
  6. dry with materialdried (MgSO4)
  7. filtrationfiltered
  8. concentrationconcentrated

Sources & evidence

ORD record
ord-7d294206cf924ae59b43156e8737bfcc
Source dataset
uspto-grants-2015_02
Patent number
US08946195B2

Reaction notes

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