Sulfuric Acid → 3-Tolylboronic acid

HRID 2081157Notes

Reaction equation

HRID 2081157 reaction equation
Br[C:2]1[CH:3]=[C:4]([CH3:8])[CH:5]=[CH:6][CH:7]=1.[Mg].[B:10](OC)([O:13]C)[O:11]C.S(=O)(=O)(O)O>CCOCC>[C:4]1([CH3:8])[CH:5]=[CH:6][CH:7]=[C:2]([B:10]([OH:13])[OH:11])[CH:3]=1

Participants

6

Reactant 4

HCID 1118Sulfuric AcidHCID 8470Trimethyl borateHCID 115603-BromotolueneHCID 5462224Magnesium

Product 1

HCID 27339503-Tolylboronic acid

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent3×

Procedure

A solution of m-bromotoluene (25 g. 0.146 mol) in ether (200 ml) was added dropwise to magnesium (4.0 g, 0.17 mol) in ether (50 ml) at room temperature over a period of 3 hours under a nitrogen atmosphere. After the addition, the reaction mixture was stirred for 12 hours at room temperature. The Grignard reagent was added slowly to a solution of trimethyl borate (15.6 g, 17 ml, 0.15 mol) in ether (500 ml) over a period of 4hours at -78° C. and stirred for 12 hours at room temperature. The reaction mixture was hydrolyzed with 30% sulfuric acid (50 ml). The ether layer was separated, washed with water (3×250 ml) and dried over Na2SO4. The solvent was removed on a rotary evaporator and the solid obtained was recrystallized from water. M.P. 160°-161° C.

Workup

  1. additionAfter the addition
  2. stirringstirred for 12 hours at room temperature
  3. customThe ether layer was separated
  4. washwashed with water (3×250 ml)
  5. dry with materialdried over Na2SO4
  6. customThe solvent was removed on a rotary evaporator
  7. customthe solid obtained
  8. customwas recrystallized from water

Sources & evidence

ORD record
ord-6925b7cc5abf4b4eb4477b2b0737c599
Source dataset
uspto-grants-1993_02
Patent number
US05183653

Reaction notes

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