Hydrochloric Acid → (2,2-dimethyl-2H-chromen-6-yl)boronic acid

HRID 1673843Notes

Reaction equation

HRID 1673843 reaction equation
Br[C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[O:8][C:7]([CH3:13])([CH3:12])[CH:6]=[CH:5]2.C([Li])CCC.[B:19](OC(C)C)([O:24]C(C)C)[O:20]C(C)C.Cl>O1CCCC1>[CH3:12][C:7]1([CH3:13])[CH:6]=[CH:5][C:4]2[C:9](=[CH:10][CH:11]=[C:2]([B:19]([OH:24])[OH:20])[CH:3]=2)[O:8]1

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 21531Triisopropyl borateHCID 117705336-Bromo-2,2-dimethyl-2H-chromeneHCID 178418339Butyllithium

Product 1

HCID 17750385(2,2-dimethyl-2H-chromen-6-yl)boronic acidYield 82%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 6-bromo-2,2-dimethyl-2H-chromene (18 g) in tetrahydrofuran (150 mL) was added butyllithium (53 mL, 1.6 M hexane solution) at −78° C. under an argon atmosphere, and the mixture was stirred for 30 min. Triisopropyl borate (21 mL) was added, and the mixture was stirred for 3 hr while allowing to warm to room temperature. 1 M hydrochloric acid (150 mL) was added to the reaction mixture, and the mixture was stirred for 2 hr and extracted with ethyl acetate. The organic layer was washed with saturated brine and dried over anhydrous magnesium sulfate, and the solvent was evaporated. The residue was purified by silica gel column chromatography to give the title compound (13 g, 82%) as colorless crystals.

Workup

  1. stirringthe mixture was stirred for 3 hr
  2. stirringthe mixture was stirred for 2 hr
  3. extractionextracted with ethyl acetate
  4. washThe organic layer was washed with saturated brine
  5. dry with materialdried over anhydrous magnesium sulfate
  6. customthe solvent was evaporated
  7. customThe residue was purified by silica gel column chromatography

Sources & evidence

ORD record
ord-eeb6c961bacf41a7a8137c9beb5f1177
Source dataset
uspto-grants-2011_08
Patent number
US07998968B2

Reaction notes

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