Trimethyl borate → 4-Ethoxy-3-fluoro-2-formylphenylboronic acid

HRID 718484Notes

Reaction equation

[Li]CCCC.Br[C:7]1[C:12]([CH:13]2OCC[O:14]2)=[C:11]([F:18])[C:10]([O:19][CH2:20][CH3:21])=[CH:9][CH:8]=1.[B:22](OC)([O:25]C)[O:23]C>C1COCC1>[CH2:20]([O:19][C:10]1[CH:9]=[CH:8][C:7]([B:22]([OH:25])[OH:23])=[C:12]([CH:13]=[O:14])[C:11]=1[F:18])[CH3:21]

Participants

Conditions

Temperature: -70 °C

Procedure

Under a nitrogen atmosphere, n-BuLi (43.3 mL, 71.42 mmol) was slowly added dropwise, at −70° C. or lower, to a THF (200 mL) solution of compound (54) (19.8 g, 68.02 mmol). The reaction mixture was agitated at −70° C. or lower for 1 hour, and then trimethyl borate (10.6 g, 102.0 mmol) was slowly added dropwise thereto. The reaction mixture was returned to room temperature, and then quenched with 200 mL of 2N hydrochloric acid aqueous solution, and extracted with 100 mL of toluene three times. Combined organic layers were washed with a saturated aqueous solution of sodium hydrogencarbonate, water and saturated brine, and then dried over magnesium sulfate, and a solvent was distilled off by an evaporator. The residue was washed with heptane, and thus (4-ethoxy-3-fluoro-2-formylphenyl)boronic acid (55) (9.85 g, yield 68.3%) was obtained.

Workup

customwas returned to room temperature
customquenched with 200 mL of 2N hydrochloric acid aqueous solution
extractionextracted with 100 mL of toluene three times
washCombined organic layers were washed with a saturated aqueous solution of sodium hydrogencarbonate, water and saturated brine
dry with materialdried over magnesium sulfate
distillationa solvent was distilled off by an evaporator
washThe residue was washed with heptane

Sources & evidence

ORD record: ord-8f159497c2f04ec197d2f92f54293010
Source dataset: uspto-grants-2015_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09193908B2

Reaction notes

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