Trimethyl borate → (5-Ethoxy-2,4-difluorophenyl)boronic acid

HRID 1438148Notes

Reaction equation

HRID 1438148 reaction equation
Br[C:2]1[CH:7]=[C:6]([O:8][CH2:9][CH3:10])[C:5]([F:11])=[CH:4][C:3]=1[F:12].[Li]CCCC.[B:18](OC)([O:21]C)[O:19]C>C1COCC1>[CH2:9]([O:8][C:6]1[C:5]([F:11])=[CH:4][C:3]([F:12])=[C:2]([B:18]([OH:21])[OH:19])[CH:7]=1)[CH3:10]

Participants

5

Reactant 3

HCID 8470Trimethyl borateHCID 579426611-Bromo-5-ethoxy-2,4-difluorobenzeneHCID 178418339Butyllithium

Product 1

HCID 53216558(5-Ethoxy-2,4-difluorophenyl)boronic acidYield 70%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To 97D (670 mg, 2.83 mmol) in THF (10 mL) was added n-BuLi (1.6M in hexane, 2.3 mL) at −78° C. After stirring for 15 min, trimethyl borate (0.634 mL) was introduced. The mixture was stirred from −78° C. to rt for 5 h before it was quenched by 1N HCl. It was extracted with ethyl acetate. The organic extract was washed with saturated Na2S2O3, brine and dried over MgSO4. The crude product was purified by column chromatography to give 97E (400 mg, 70% yield) as a solid.

Workup

  1. stirringThe mixture was stirred from −78° C. to rt for 5 h before it
  2. customwas quenched by 1N HCl
  3. extractionIt was extracted with ethyl acetate
  4. extractionThe organic extract
  5. washwas washed with saturated Na2S2O3, brine
  6. dry with materialdried over MgSO4
  7. customThe crude product was purified by column chromatography

Sources & evidence

ORD record
ord-ca55ddf56e0d445ca23eb406d987d1f9
Source dataset
uspto-grants-2009_11
Patent number
US07622585B2

Reaction notes

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