Hydrochloric Acid → (4-Cyclopropoxyphenyl)boronic acid

HRID 646152Notes

Reaction equation

HRID 646152 reaction equation
Br[C:2]1([O:8][CH:9]2[CH2:11][CH2:10]2)[CH:7]=[CH:6][CH:5]=[CH:4][CH2:3]1.[Li]CCCC.[B:17](OCC)([O:21]CC)[O:18]CC.Cl>C1COCC1>[CH:9]1([O:8][C:2]2[CH:7]=[CH:6][C:5]([B:17]([OH:21])[OH:18])=[CH:4][CH:3]=2)[CH2:11][CH2:10]1

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 9009Triethyl borateHCID 686990414-Bromo-4-cyclopropoxybenzeneHCID 178418339Butyllithium

Product 1

HCID 53216708(4-Cyclopropoxyphenyl)boronic acidYield 36%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 4-bromo-4-cyclopropoxybenzene (5.0 g, 23.4 mmol, see Example 39(c)) in THF (80 mL) at −78° C. was added n-BuLi (2.5 M solution in hexane; 9.76 mL, 24.4 mmol) over 17 min. After 40 min, B(OEt)3 (5.9 mL, 34.3 mmol) was added and the reaction was warmed to room temperature and stirred at ambient temperature for 18 h. After re-cooling to 0° C., HCl (1M solution; 70 mL, aq.) was added. After 30 min the mixture was extracted with t-BuOMe (3×50 mL), the combined organic extracts were washed with brine, dried (Na2SO4) and concentrated. The residue was washed with light petrol and filtered yielding the sub-title compound (1.5 g, 34%).

Workup

  1. temperatureAfter re-cooling to 0° C.
  2. extractionAfter 30 min the mixture was extracted with t-BuOMe (3×50 mL)
  3. washthe combined organic extracts were washed with brine
  4. dry with materialdried (Na2SO4)
  5. concentrationconcentrated
  6. washThe residue was washed with light petrol
  7. filtrationfiltered

Sources & evidence

ORD record
ord-821109ee1aad4d8490dc0337242d8313
Source dataset
uspto-grants-2010_04
Patent number
US07705023B2

Reaction notes

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