Hydrochloric Acid → 4-[(Tert-butyldimethylsilyl)oxy]-2,6-dimethylphenylboronic acid

Temperature

-78 °C

To a solution (250 mL) of (4-bromo-3,5-dimethylphenoxy)(tert-butyl)dimethylsilane (39.2 g, 124 mmol) in tetrahydrofuran was added n-butyllithium hexane solution (1.6 M, 90.0 mL, 144 mmol) under stirring at −78° C. The reaction mixture was stirred at the same temperature for 2 hr, and triisopropyl borate (40.0 mL, 173 mmol) was added. The mixture was allowed to warm to room temperature and stirred for 3 hr. To the reaction mixture was added 2 M hydrochloric acid (180 mL), and the mixture was stirred for 6 hr. The reaction mixture was partitioned between ethyl acetate and water. The organic layer was dried over magnesium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel chromatography (hexane/ethyl acetate=10/1-hexane/ethyl acetate=1/4) to give the title compound (18.6 g, yield 53%) as pale-yellow prism crystals.

1. stirringThe reaction mixture was stirred at the same temperature for 2 hr
2. temperatureto warm to room temperature
3. stirringstirred for 3 hr
4. stirringthe mixture was stirred for 6 hr
5. customThe reaction mixture was partitioned between ethyl acetate and water
6. dry with materialThe organic layer was dried over magnesium sulfate
7. concentrationconcentrated under reduced pressure
8. customThe residue was purified by silica gel chromatography (hexane/ethyl acetate=10/1-hexane/ethyl acetate=1/4)

ORD record

ord-304bbe42224541f0bc4645e42bdcf7e0

Source dataset

uspto-grants-2010_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07786165B2