Tributyl borate → (2-ethyl-4-methoxyphenyl)boronic acid

HRID 2422364Notes

Reaction equation

HRID 2422364 reaction equation
Br[C:2]1[CH:7]=[CH:6][C:5]([O:8][CH3:9])=[CH:4][C:3]=1[CH2:10][CH3:11].C([Li])CCC.[B:17](OCCCC)([O:23]CCCC)[O:18]CCCC>C1COCC1>[CH2:10]([C:3]1[CH:4]=[C:5]([O:8][CH3:9])[CH:6]=[CH:7][C:2]=1[B:17]([OH:23])[OH:18])[CH3:11]

Participants

5

Reactant 3

HCID 12712Tributyl borateHCID 123866191-BROMO-2-ETHYL-4-METHOXY-BENZENEHCID 178418339Butyllithium

Product 1

HCID 11506554(2-ethyl-4-methoxyphenyl)boronic acid

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
0 °C

Procedure

A solution of 4-bromo-3-ethyl anisole (94 g, 0.437 mol) in THF (900 ml) was cooled to −78° C. n-Butyl lithium (249 ml, 0.55 mol) was added dropwise at the same temperature. Stirring was continued for 1 hr at −78° C. Tri-n-butyl borate (177 ml, 0.655 mol) was added slowly at −78° C. The cooling bath was removed, the reaction mixture was allowed to warm to 0° C. and was quenched with 1.5 N hydrochloric acid at 0° C. The organic layer was separated. The aqueous layer was extracted with ethylacetate and the combined organic layers were washed with brine and concentrated. The residue obtained was stirred in petroleum ether for 30 min. The solid obtained was filtered and dried under vacuum. Yield: 65 g, 82%, as a white solid.

Workup

  1. additionwas added dropwise at the same temperature
  2. customThe cooling bath was removed
  3. customwas quenched with 1.5 N hydrochloric acid at 0° C
  4. customThe organic layer was separated
  5. extractionThe aqueous layer was extracted with ethylacetate
  6. washthe combined organic layers were washed with brine
  7. concentrationconcentrated
  8. customThe residue obtained
  9. customThe solid obtained
  10. filtrationwas filtered
  11. customdried under vacuum

Sources & evidence

ORD record
ord-79297b6526e8447bbf326fd1a6530edc
Source dataset
uspto-grants-2011_06
Patent number
US07960349B2

Reaction notes

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