Triisopropyl borate → (3-Chloro-2-methylphenyl)boronic acid

HRID 547749Notes

Reaction equation

HRID 547749 reaction equation
Br[C:2]1[CH:7]=[CH:6][CH:5]=[C:4]([Cl:8])[C:3]=1[CH3:9].[B:10](OC(C)C)([O:15]C(C)C)[O:11]C(C)C>C1COCC1>[Cl:8][C:4]1[C:3]([CH3:9])=[C:2]([B:10]([OH:15])[OH:11])[CH:7]=[CH:6][CH:5]=1

Participants

4

Reactant 2

HCID 21531Triisopropyl borateHCID 1235522-Bromo-6-chlorotoluene

Product 1

HCID 3744103(3-Chloro-2-methylphenyl)boronic acidYield 61.2%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 10.0 g (48.7 mmol) 2-bromo-6-chlorotoluene and 11.3 ml (48.7 mmol) triisopropyl borate in 90 ml dry THF were added dropwise 30 ml (49 mmol) of a 1.6 M solution on n-butyllithium in hexanes at −78° C. under argon. After 45 min the reaction mixture was allowed to warm to room temperature. The reaction was quenched by addition of 5 ml water and the solvent was evaporated in vacuo. Addition of 1 M aqueous hydrochloric acid solution was followed by extraction with four portions of dichloromethane. The combined organic extracts were dried over sodium sulfate and concentrated in vacuo. Crystallisation from heptane gave 5.08 g (61%) of the title compound as a white solid.

Workup

  1. customThe reaction was quenched by addition of 5 ml water
  2. customthe solvent was evaporated in vacuo
  3. additionAddition of 1 M aqueous hydrochloric acid solution
  4. extractionwas followed by extraction with four portions of dichloromethane
  5. dry with materialThe combined organic extracts were dried over sodium sulfate
  6. concentrationconcentrated in vacuo
  7. customCrystallisation from heptane

Sources & evidence

ORD record
ord-a407ae54af7f4e53b49fa2480e980722
Source dataset
uspto-grants-2011_05
Patent number
US07939533B2

Reaction notes

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