Triisopropyl borate → (4-Chloro-3-ethoxyphenyl)boronic acid

HRID 1438124Notes

Reaction equation

HRID 1438124 reaction equation
Br[C:2]1[CH:7]=[CH:6][C:5]([Cl:8])=[C:4]([O:9][CH2:10][CH3:11])[CH:3]=1.[Li]CCCC.[B:17](OC(C)C)([O:22]C(C)C)[O:18]C(C)C>C1COCC1>[Cl:8][C:5]1[CH:6]=[CH:7][C:2]([B:17]([OH:22])[OH:18])=[CH:3][C:4]=1[O:9][CH2:10][CH3:11]

Participants

5

Reactant 3

HCID 21531Triisopropyl borateHCID 509981874-Bromo-1-chloro-2-ethoxybenzeneHCID 178418339Butyllithium

Product 1

HCID 23005379(4-Chloro-3-ethoxyphenyl)boronic acidYield 57.7%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 31A (3.8 g, 16 mmol) in THF (20 mL) at −78° C. was added n-BuLi (1.6 M in hexanes, 13.6 mL, 21.8 mmol). The mixture was stirred at −78° C. for 40 min before triisopropyl borate (7.43 mL, 32 mmol) was added. The reaction was left stirring, from −78° C. to rt over 18 h. It was quenched with 1.0 N HCl (50 mL), extracted with EtOAc, washed with brine and dried over Na2SO4. The crude residue was purified by flash column chromatography (CH2Cl2: EtOAc: MeOH=50:50:1) to give 1.85 g (57%) of 31B as a white solid. 1H NMR (400 MHz, CDCl3) δ ppm 1.53 (t, J=7.03 Hz, 3H) 4.23 (d, J=7.03 Hz, 2H) 7.48 (d, J=7.91 Hz, 1H) 7.66 (d, J=6.15 Hz, 2H).

Workup

  1. additionwas added
  2. waitThe reaction was left
  3. customIt was quenched with 1.0 N HCl (50 mL)
  4. extractionextracted with EtOAc
  5. washwashed with brine
  6. dry with materialdried over Na2SO4
  7. customThe crude residue was purified by flash column chromatography (CH2Cl2: EtOAc: MeOH=50:50:1)

Sources & evidence

ORD record
ord-38ae7515c79949af8b1d1ae9c5054860
Source dataset
uspto-grants-2009_11
Patent number
US07622585B2

Reaction notes

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