Hydrochloric Acid → 2-Methyl-4-methylthiophenylboronic acid

HRID 748910Notes

Reaction equation

HRID 748910 reaction equation
Br[C:2]1[CH:7]=[CH:6][C:5]([S:8][CH3:9])=[CH:4][C:3]=1[CH3:10].[Li]C(C)(C)C.[B:16](OC)([O:19]C)[O:17]C.Cl>C(OCC)C>[CH3:10][C:3]1[CH:4]=[C:5]([S:8][CH3:9])[CH:6]=[CH:7][C:2]=1[B:16]([OH:19])[OH:17]

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 8470Trimethyl borateHCID 26370189(4-Bromo-3-methylphenyl)(methyl)sulfaneHCID 178418306HCID 178418306, compound

Product 1

HCID 225912982-Methyl-4-methylthiophenylboronic acidYield 52.4%

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent

Conditions

Temperature
-78 °C

Procedure

Add 1-bromo-2-methyl-4-methylsulfanyl-benzene (608 mg, 2.80 mmol) to diethyl ether (60 mL) and cool to −78° C. under a nitrogen blanket. Add t-BuLi (3.4 mL, 5.78 mmol) over a 15 minute period, stir for 2 minutes, add trimethyl borate ((MeO)3B, 340 μL, 2.99 mmol) over 2 minutes, stir for 15 minutes at −78° C. and then let warm to room temperature. Quench the reaction with saturated aqueous NH4Cl (7 mL), stir for 15 minutes, add 1M aqueous HCl (6 mL), stir for another 2 minutes and separate. Dry with Na2SO4, filter (wash the drying agent with ethyl acetate (3×20 mL)), and concentrate. Chromatograph the crude material on a SiO2 column with 20% ethyl acetate in hexanes to 5% methanol in ethyl acetate to give 267 mg of the title compound (52%).

Workup

  1. stirringstir for 15 minutes at −78° C.
  2. temperaturelet warm to room temperature
  3. customQuench
  4. customthe reaction with saturated aqueous NH4Cl (7 mL)
  5. stirringstir for 15 minutes
  6. stirringstir for another 2 minutes
  7. customseparate
  8. dry with materialDry with Na2SO4
  9. filtrationfilter (
  10. washwash the drying agent with ethyl acetate (3×20 mL)), and
  11. concentrationconcentrate

Sources & evidence

ORD record
ord-113c48ecda63435db757b113e0cfbfed
Source dataset
uspto-grants-2008_07
Patent number
US07399867B2

Reaction notes

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