Sulfuric Acid → 3,5-Dimethylphenylboronic acid

HRID 1372540Notes

Reaction equation

HRID 1372540 reaction equation
[CH3:1][C:2]1[CH:3]=[C:4](Br)[CH:5]=[C:6]([CH3:8])[CH:7]=1.[Mg].C([O:14][B:15](OC(C)C)[O:16]C(C)C)(C)C.S(=O)(=O)(O)O>C1COCC1.C(OCC)C>[CH3:1][C:2]1[CH:3]=[C:4]([B:15]([OH:16])[OH:14])[CH:5]=[C:6]([CH3:8])[CH:7]=1

Participants

7

Reactant 4

HCID 1118Sulfuric AcidHCID 21531Triisopropyl borateHCID 136357Benzene, 1-bromo-3,5-dimethyl-HCID 5462224Magnesium

Product 1

HCID 27343493,5-Dimethylphenylboronic acid

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolvent2×HCID 8028TetrahydrofuranSolvent

Procedure

3,5-Dimethylbromobenzene (10 g, 54 mmol) and magnesium (2.5 g, 108 mmol) were dissolved in 100 mL of THF and stirred at reflux for five hours. After this time, triisopropylborate (10 g, 54 mmol) as a solution in diethylether (50 mL) was added to the solution, followed by stirring at room temperature overnight. The THF was removed in vacuo to leave a crude oil. This oil was taken up in 100 mL of diethylether and 100 mL of 10% sulfuric acid (aqueous) and stirred for two hours. The organic layer was separated and neutralized with saturated sodium bicarbonate solution, whereafter the solvent was removed in vacuo to yield a white solid. The solid was washed generously with pentane. Yield: 4.0 g (49%).

Workup

  1. temperatureat reflux for five hours
  2. stirringby stirring at room temperature overnight
  3. customThe THF was removed in vacuo
  4. customto leave a crude oil
  5. customThe organic layer was separated
  6. customwas removed in vacuo
  7. customto yield a white solid
  8. washThe solid was washed generously with pentane

Sources & evidence

ORD record
ord-d09b3ff3908441bab05bef7051b18c92
Source dataset
uspto-grants-2007_01
Patent number
US07157591B2

Reaction notes

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