Trimethyl borate → 5-(But-3-enyloxy)-2,4-dimethylphenylboronic acid
Reaction equation
Br[C:2]1[CH:7]=[C:6]([O:8][CH2:9][CH2:10][CH:11]=[CH2:12])[C:5]([CH3:13])=[CH:4][C:3]=1[CH3:14].[Li]CCCC.C[O:21][B:22](OC)[O:23]C>C1COCC1>[CH2:9]([O:8][C:6]1[C:5]([CH3:13])=[CH:4][C:3]([CH3:14])=[C:2]([B:22]([OH:23])[OH:21])[CH:7]=1)[CH2:10][CH:11]=[CH2:12]Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- -70 °C
Procedure
In the glovebox, a 100-mL round bottomed flask is charged with 1-bromo-5-(but-3-enyloxy)-2,4-dimethylbenzene (3.142 g, 13.6 mmol) and THF (100 mL). The flask is sealed with a septum and removed from the glovebox. The flask is cooled to −70° C. under nitrogen purge. BuLi (1.6M in hexanes, 8.2 mL, 13 mmol) is added slowly, keeping the temperature below −68° C., and the reaction mixture is stirred for one hr at −70° C. Trimethylborate (1.3 mL, 12 mmol) is added, and the mixture is stirred as it slowly warms to room temperature. Solvents are removed on a rotovap, and ice (60 g) containing hydrochloric acid (HCl) (conc, 5 mL) is added, and then ether (60 mL). A white precipitate forms, and this is collected on a fine frit. Yield=1.283 g of a white solid. 1H NMR is taken by suspending the solid in d6-dimethylsulfoxide (d6-DMSO) and adding a trace of HCl.
Workup
- customThe flask is sealed with a septum
- customremoved from the glovebox
- custompurge
- customthe temperature below −68° C.
- stirringthe mixture is stirred as it
- customslowly warms to room temperature
- customSolvents are removed on a rotovap, and ice (60 g)
- additioncontaining hydrochloric acid (HCl) (conc, 5 mL)
- additionis added
- customA white precipitate forms, and this is collected on a fine frit
- additionadding a trace of HCl
Sources & evidence
- ORD record
- ord-dc57b468d13248719da06258644bfa94
- Source dataset
- uspto-grants-2013_11
- Patent number
- US08592615B2
Reaction notes
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