Trimethyl borate → 4-Fluoro-3-(hydroxymethyl)benzeneboronic acid
Reaction equation
Br[C:2]1[CH:9]=[CH:8][C:5]([CH2:6][OH:7])=[C:4]([F:10])[CH:3]=1.[Li]CCCC.C[O:17][B:18](OC)[O:19]C>Cl.C(OCC)(=O)C>[F:10][C:4]1[CH:3]=[CH:2][C:9]([B:18]([OH:19])[OH:17])=[CH:8][C:5]=1[CH2:6][OH:7]Participants
6
Conditions
- Temperature
- 21 °C
Procedure
To a solution of 4-bromo-2-fluoro-benzyl alcohol (10 g, 49 mmol) in TBF (500 mL) at −78° C. was added BuLi (2.5M, 43 mL, 107 mmol) dropwise keeping the internal temperature below −73° C. After 25 min., trimethylborate (25 mL, 107 mmol) was added and the resulting reaction mixture stirred for 15 h at −78° C., 1 h at 21° C., then diluted with HCl 10% and ethyl acetate. The organic extracts were washed (H2O, brine), dried (MgSO4), filtered and concentrated. The residue was solidified from hexane/ethyl acetate with water (5 drops) to afford the 4-fluoro-3-hydroxymethyl-benzene-boronic acid compound as a white solid.
Workup
- customthe internal temperature below −73° C
- customthe resulting reaction mixture
- washThe organic extracts were washed (H2O, brine)
- dry with materialdried (MgSO4)
- filtrationfiltered
- concentrationconcentrated
Sources & evidence
- ORD record
- ord-14da546c070e43489b83f3f526b5603a
- Source dataset
- uspto-grants-2005_07
- Patent number
- US06919353B2
Reaction notes
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