Triisopropyl borate → 4-tert-Butoxyphenylboronic acid

HRID 1600921Notes

Reaction equation

HRID 1600921 reaction equation
C([Li])(C)(C)C.[C:6]([O:10][C:11]1[CH:16]=[CH:15][C:14](Br)=[CH:13][CH:12]=1)([CH3:9])([CH3:8])[CH3:7].[B:18](OC(C)C)([O:23]C(C)C)[O:19]C(C)C.[Cl-].[NH4+]>O1CCCC1.CCOCC>[C:6]([O:10][C:11]1[CH:16]=[CH:15][C:14]([B:18]([OH:23])[OH:19])=[CH:13][CH:12]=1)([CH3:9])([CH3:8])[CH3:7]

Participants

7

Reactant 4

HCID 21531Triisopropyl borateHCID 25517Ammonium ChlorideHCID 27639591-Bromo-4-(tert-butoxy)benzeneHCID 178418306HCID 178418306, compound

Product 1

HCID 113899354-tert-Butoxyphenylboronic acid

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolventHCID 8028TetrahydrofuranSolvent2×

Procedure

A solution of tert-butyllithium (1.7 M in pentane, 12 ml, CAUTION-PYROPHORIC) was added dropwise to a stirring solution of 4-bromophenyl tert-butyl ether (2.33 g) in tetrahydrofuran (20 ml) at -70° C. After a further 5 minutes the resulting solution of anion was added dropwise to a solution of triisopropyl borate (6 ml) in tetrahydrofuran (10 ml) at -70 ° C. After the addition was complete the reaction mixture was allowed to warm to room temperature. After 20 minutes a solution of saturated aqueous ammonium chloride (25 ml) and ether (25 ml) was added. The layers were separated and the aqueous phase washed with ether (50 ml). The combined organic extracts were washed with dilute hydrochloric acid (5%, 25 ml) and were then dried over anhydrous magnesium sulfate. The solution was filtered and concentrated under reduced pressure to give a white solid. This was purified by column chromatography over silica eluting with ether then methanol to give the sub-title compound as a white solid (0.69 g).

Workup

  1. additionAfter the addition
  2. customThe layers were separated
  3. washthe aqueous phase washed with ether (50 ml)
  4. washThe combined organic extracts were washed with dilute hydrochloric acid (5%, 25 ml)
  5. dry with materialwere then dried over anhydrous magnesium sulfate
  6. filtrationThe solution was filtered
  7. concentrationconcentrated under reduced pressure
  8. customto give a white solid
  9. customThis was purified by column chromatography over silica eluting with ether

Sources & evidence

ORD record
ord-9d419f10bead493593b610c80993f2a7
Source dataset
uspto-grants-1999_11
Patent number
US05977105

Reaction notes

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