Hydrochloric Acid → 2-Propoxy-3,5-diisopropyl-phenylboronic acid

HRID 1883224Notes

Reaction equation

[Li]CCCC.Br[C:7]1[CH:12]=[C:11]([CH:13]([CH3:15])[CH3:14])[CH:10]=[C:9]([CH:16]([CH3:18])[CH3:17])[C:8]=1[O:19][CH2:20][CH2:21][CH3:22].[B:23](OC(C)C)([O:28]C(C)C)[O:24]C(C)C.Cl>C1COCC1>[CH2:20]([O:19][C:8]1[C:9]([CH:16]([CH3:18])[CH3:17])=[CH:10][C:11]([CH:13]([CH3:15])[CH3:14])=[CH:12][C:7]=1[B:23]([OH:28])[OH:24])[CH2:21][CH3:22]

Participants

Conditions

Temperature: -78 °C

Procedure

To a solution of n-BuLi (1.6 M in hexane, 40 mL, 64.2 mmol) in THF (150 mL) at −78° C. was added 1-bromo-3,5-diisopropyl-2-propoxy-benzene (Intermediate 3,16.0 g, 53.5 mmol) in THF (50 mL and 10 mL rinse) slowly. Thereafter 0.5 h triisopropyl borate (24.7 mL, 107 mmol) in THF (40 mL) was added slowly and the reaction was stirred at −78° C. for 1 h and at room temperature for 2 h. The reaction was then treated with 3M HCl (200 mL) at room temperature for 1.5 h, and extracted with EtOAc (×2). The organic layer was washed with brine, dried over Na2SO4, and concentrated in vacuo. The crude product was washed with hexane to give 3.28 g of the title compound as a white solid. The hexane solution was filtered through a pad of SiO2 to give additional 11.0 g of the title compound as a yellow slurry containing minor impurities. This crude material was used in the next step without flirter purification.

Workup

extractionextracted with EtOAc (×2)
washThe organic layer was washed with brine
dry with materialdried over Na2SO4
concentrationconcentrated in vacuo
washThe crude product was washed with hexane

Sources & evidence

ORD record: ord-c699622106c94ebc92f1253c09d6e8cf
Source dataset: uspto-grants-2004_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06759546B1

Reaction notes

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