Tributyl borate → (4-Bromo-5-methylthiophen-2-yl)boronic acid

HRID 2068444Notes

Reaction equation

HRID 2068444 reaction equation
C([Li])CCC.[Br:6][C:7]1[CH:11]=[C:10](Br)[S:9][C:8]=1[CH3:13].C([O:18][B:19](OCCCC)[O:20]CCCC)CCC>CCCCCC.CCOCC>[Br:6][C:7]1[CH:11]=[C:10]([B:19]([OH:20])[OH:18])[S:9][C:8]=1[CH3:13]

Participants

6

Reactant 3

HCID 12712Tributyl borateHCID 1223733,5-Dibromo-2-methylthiopheneHCID 178418339Butyllithium

Product 1

HCID 12184011(4-Bromo-5-methylthiophen-2-yl)boronic acid

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolventHCID 8058HexaneSolvent

Procedure

n-Butyl lithium in hexane is added to a stirred solution of compound 2 in dry ether (150 mL) at −78° C. under argon atmosphere. After stirring for 30 min, boric acid tri-butyl ester is quickly added to the reaction mixture. The mixture is extracted with 4% aq. NaOH (100 mL), the extract is collected and neutralized by with 10% HCl. The solid residue is washed, filtrated, and dried. Compound 3 is obtained as a yellowish solid. M.p. 229° C.

Workup

  1. extractionThe mixture is extracted with 4% aq. NaOH (100 mL)
  2. customthe extract is collected
  3. washThe solid residue is washed
  4. filtrationfiltrated
  5. customdried

Sources & evidence

ORD record
ord-d76ef1c571df40d7a30aea177c86214c
Source dataset
uspto-grants-2012_10
Patent number
US08298453B2

Reaction notes

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