Hydrochloric Acid → (3-Bromo-2-fluorophenyl)boronic acid

HRID 1018402Notes

Reaction equation

HRID 1018402 reaction equation
C([Li])CCC.[Br:6][C:7]1[CH:12]=[CH:11][CH:10]=[C:9](Br)[C:8]=1[F:14].[B:15](OC)([O:18]C)[O:16]C.Cl>CCCCCC.C(OCC)C.O>[Br:6][C:7]1[C:8]([F:14])=[C:9]([B:15]([OH:18])[OH:16])[CH:10]=[CH:11][CH:12]=1

Participants

8

Reactant 4

HCID 313Hydrochloric AcidHCID 8470Trimethyl borateHCID 140714601,3-Dibromo-2-fluorobenzeneHCID 178418339Butyllithium

Product 1

HCID 16217170(3-Bromo-2-fluorophenyl)boronic acid

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 3283Diethyl EtherSolventHCID 8058HexaneSolvent

Procedure

290 ml of a 1.6 molar solution of butyllithium in hexane are added dropwise at −70° C. to a solution of 112 g of 2,6-dibromofluorobenzene [1435-54-7] in 1000 ml of diethyl ether. After the mixture has been kept at the same temperature for 2 hours, 60 ml of trimethyl borate are added, and the mixture is stirred at this temperature for 12 hours. After the mixture has been slowly warmed to room temperature, 300 ml of water are added, and the pH is adjusted to 1 by addition of hydrochloric acid. The organic phase is separated off, the aqueous phase is extracted twice with 100 ml of ether each time, and the combined organic phases are dried under reduced pressure, giving 91 g of 3-bromo-2-fluorophenylboronic acid (mixed with its cyclic anhydride) as a brown solid; 1H-NMR (DMSO-d6): 7.1-7.7 (m) ppm, 19F-NMR (DMSO-d6): −99 ppm.

Workup

  1. customThe organic phase is separated off
  2. extractionthe aqueous phase is extracted twice with 100 ml of ether each time
  3. customthe combined organic phases are dried under reduced pressure

Sources & evidence

ORD record
ord-6d2e62cd092b4c0c8def6d7daa57c2c9
Source dataset
uspto-grants-2002_11
Patent number
US06482478B1

Reaction notes

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