4-Bromobiphenyl → 1,1'-Biphenyl-4-yl-boronic acid

HRID 613839Notes

Reaction equation

HRID 613839 reaction equation
Br[C:2]1[CH:7]=[CH:6][C:5]([C:8]2[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=2)=[CH:4][CH:3]=1.C([Li])CCC.C([O:22][B:23](OC(C)C)[O:24]C(C)C)(C)C>C1COCC1>[C:5]1([C:8]2[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=2)[CH:6]=[CH:7][C:2]([B:23]([OH:24])[OH:22])=[CH:3][CH:4]=1

Participants

5

Procedure

4-Biphenylboronic acid was prepared differently than described in the literature (see Yabroff, D. L.; Branch, G. E.; Bettman, B. J. Am. Chem. Soc. 1934, 56, 1850-1857). To a solution of 4-bromobiphenyl (2.00 g, 8.58 mmol) in THF (20 mL) at -78° C. was added n-butyllithium (4.0 mL of 2.5 M in hexanes) in a slow stream via syringe. After 15 minutes, triisopropylborate (3.0 mL, 13 mmol) was added in a slow stream via syringe. After 10 minutes, the resultant homogeneous solution was allowed to warm to ambient temperature over 45 minutes and partitioned between EtOAc (50 mL) and 10% aqueous HCI (50 mL). The aqueous layer was separated and extracted with more EtOAc. The combined organic layers were washed with brine, dried over Na2SO4 and concentrated to give a crude product which was triturated with hexanes to yield 1.53 g (90%) of 4-biphenylboronic acid as a white solid. 1H NMR (DMSO-d6): δ 8.05 (s, 2H), 7.83 (d, 2H, J=8.5 Hz), 7.65 (d, 2H, J=7.0 Hz), 7.60 (d, 2H, J=8.1 Hz), 7.43 (t, 2H, J=7.4 Hz), 7.33 (t, 1H, J=7.2 Hz). Anal. C12H11BO2 : C, 72.78; H, 560. Found: C, 72.51; H, 5.62.

Workup

  1. waitAfter 10 minutes
  2. custompartitioned between EtOAc (50 mL) and 10% aqueous HCI (50 mL)
  3. customThe aqueous layer was separated
  4. extractionextracted with more EtOAc
  5. washThe combined organic layers were washed with brine
  6. dry with materialdried over Na2SO4
  7. concentrationconcentrated
  8. customto give a crude product which

Sources & evidence

ORD record
ord-8feefe12186e45daa1305d5de090b428
Source dataset
uspto-grants-1999_12
Patent number
US06008243

Reaction notes

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