Hydrochloric Acid → 4-(Benzyloxy)-2-vinylphenylboronic acid

HRID 860707Notes

Reaction equation

HRID 860707 reaction equation
[B:1](OC(C)C)([O:6]C(C)C)[O:2]C(C)C.[CH2:14]([O:21][C:22]1[CH:27]=[CH:26][C:25](Br)=[C:24]([CH:29]=[CH2:30])[CH:23]=1)[C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1.C([Li])CCC.Cl>C1COCC1.O>[CH2:14]([O:21][C:22]1[CH:27]=[CH:26][C:25]([B:1]([OH:6])[OH:2])=[C:24]([CH:29]=[CH2:30])[CH:23]=1)[C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 21531Triisopropyl borateHCID 692072164-(Benzyloxy)-1-bromo-2-vinylbenzeneHCID 178418339Butyllithium

Product 1

HCID 692054944-(Benzyloxy)-2-vinylphenylboronic acidYield 602.9%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent

Procedure

Triisopropyl borate (683 mg, 3.63 mmol) was added to a stirred solution of 4-(benzyloxy)-1-bromo-2-vinylbenzene (1.0 g, 0.346 mmol) in THF (9 mL). The solution was cooled in a CO2/acetone bath. A solution of n-butyllithium (1.45 mL of 2.5M in hexanes, 3.63 mmol) was added dropwise over 5 minutes. The cooling bath was left in place and was allowed to warm to room temperature. The mixture was treated with HCl (5 mL of 1N) and water (5 mL), stirred for 1 hour, and extracted with ethyl acetate (3×15 mL). The combined extracts were washed with brine, dried (MgSO4), filtered, and concentrated to an oil which crystallized from diethyl ether/hexanes to provide colorless crystals of the desired product (530 mg, 57% yield). 1H NMR (300 MHz, CDCl3) δ 5.14 (s, 2H), 5.34 (d, J=12.44 Hz, 1H), 5.68 (d, J=17.57 Hz, 1H), 6.97 (dd, J=8.42, 2.56 Hz, 1H), 7.36 (m, 6H), 7.83 (dd, J=17.57, 10.98 Hz, 1H), 8.16 (d, J=8.42 Hz, 1H).

Workup

  1. temperatureThe solution was cooled in a CO2/acetone bath
  2. waitThe cooling bath was left in place
  3. extractionextracted with ethyl acetate (3×15 mL)
  4. washThe combined extracts were washed with brine
  5. dry with materialdried (MgSO4)
  6. filtrationfiltered
  7. concentrationconcentrated to an oil which
  8. customcrystallized from diethyl ether/hexanes

Sources & evidence

ORD record
ord-369bb6ac04cd48e59e3dd195ae4c3b7a
Source dataset
uspto-grants-2006_12
Patent number
US07153848B2

Reaction notes

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