Trimethyl borate → (4-Chloro-3-methoxyphenyl)boronic acid
Reaction equation
Br[C:2]1[CH:7]=[CH:6][C:5]([Cl:8])=[C:4]([O:9][CH3:10])[CH:3]=1.C([Li])CCC.C[O:17][B:18](OC)[O:19]C>C1(C)C=CC=CC=1.C1COCC1>[Cl:8][C:5]1[CH:6]=[CH:7][C:2]([B:18]([OH:19])[OH:17])=[CH:3][C:4]=1[O:9][CH3:10]Participants
5
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- -78 °C
Procedure
To 4-bromo-1-chloro-2-methoxybenzene (2.2 g, 9.9 mmol) in toluene/THF (16/6 mL) at −78° C. was added n-butyl lithium (8.7 mL, 1.6 M in hexane, 14 mmol) dropwise. The reaction was stirred at −78° C. for 30 min, then trimethylborate (2.2 mL, 19.8 mmol) was added. The reaction was allowed to warm to rt and stirred overnight and then quenched with 1 M HCl (15 mL). The organic layer was separated and dried over sodium sulfate. The solvent was removed and the crude product was purified by flash column chromatography to give 25A (1.2 g, 65% yield) as a white solid. 1H NMR (400 MHz, CDOD3) δ ppm 3.87 (m, 3H) 7.11 (d, J=7.83 Hz, 1H) 7.20 (s, 1H) 7.29 (d, J=7.83 Hz, 1H).
Workup
- temperatureto warm to rt
- stirringstirred overnight
- customquenched with 1 M HCl (15 mL)
- customThe organic layer was separated
- dry with materialdried over sodium sulfate
- customThe solvent was removed
- customthe crude product was purified by flash column chromatography
Sources & evidence
- ORD record
- ord-c2c91d07c1544ee9b2eb6515c9fb6aa8
- Source dataset
- uspto-grants-2012_07
- Patent number
- US08222453B2
Reaction notes
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