Triisopropyl borate → {2-(methyloxy)-3-[(E)-2-(methyloxy)ethenyl]phenyl}boronic acid
Reaction equation
Br[C:2]1[CH:7]=[CH:6][CH:5]=[C:4](/[CH:8]=[CH:9]/[O:10][CH3:11])[C:3]=1[O:12][CH3:13].[Li]CCCC.[B:19](OC(C)C)([O:24]C(C)C)[O:20]C(C)C>O1CCCC1>[CH3:13][O:12][C:3]1[C:4](/[CH:8]=[CH:9]/[O:10][CH3:11])=[CH:5][CH:6]=[CH:7][C:2]=1[B:19]([OH:24])[OH:20]Participants
Conditions
- Temperature
- -78 °C
Procedure
To a solution of 1-bromo-2-(methyloxy)-3-[(E)-2-(methyloxy)ethenyl]benzene (D100) (930 mg, 3.83 mmol) in Tetrahydrofuran (THF) (10 mL) was added BuLi (1.989 mL, 4.97 mmol) dropwise at −78° C. under nitrogen. The reaction mixture was stirred at −78° C. for 2 hours. Tris(1-methylethyl) borate (1.319 mL, 5.74 mmol) was added to the reaction mixture by syringe at −78° C. Then the reaction was stirred at −78° C. for 30 min, and then warmed to room temperature slowly. Then the reaction was quenched with water. The mixture was extracted with EA (15 mL×3). The combined organic layers was dried over anhydrous sodium sulphate. After filtration and concentration, the crude {2-(methyloxy)-3-[(E)-2-(methyloxy)ethenyl]phenyl}boronic acid (D101) (741 mg) was used directly in the next step. MS (ES): C10H13BO4 requires 208.1. found 209.0 (M+H+)
Workup
- stirringThen the reaction was stirred at −78° C. for 30 min
- temperaturewarmed to room temperature slowly
- customThen the reaction was quenched with water
- extractionThe mixture was extracted with EA (15 mL×3)
- dry with materialThe combined organic layers was dried over anhydrous sodium sulphate
- filtrationAfter filtration and concentration
Sources & evidence
- ORD record
- ord-7c6bb231cefb4316a39223c4fab26790
- Source dataset
- uspto-grants-2013_03
- Patent number
- US08389508B2
Reaction notes
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