Potassium Acetate → (5-formyl-1-{[2-(trimethylsilyl)ethoxy]methyl}-1H-pyrazol-4-yl)boronic acid

HRID 2364055Notes

Reaction equation

Br[C:2]1[CH:3]=[N:4][N:5]([CH2:9][O:10][CH2:11][CH2:12][Si:13]([CH3:16])([CH3:15])[CH3:14])[C:6]=1[CH:7]=[O:8].CC1(C)C(C)(C)[O:21][B:20](B2OC(C)(C)C(C)(C)O2)[O:19]1.C([O-])(=O)C.[K+]>COCCOC>[CH:7]([C:6]1[N:5]([CH2:9][O:10][CH2:11][CH2:12][Si:13]([CH3:16])([CH3:15])[CH3:14])[N:4]=[CH:3][C:2]=1[B:20]([OH:21])[OH:19])=[O:8]

Participants

Conditions

Temperature: 90 °C

Procedure

A mixture of 4-bromo-1-[[2-(trimethylsilyl)ethoxy]methyl]-1H-pyrazole-5-carbaldehyde (2.00 g, 6.55 mmol), 4,4,4′,4′,5,5,5′,5′-octamethyl-2,2′-bi-1,3,2-dioxaborolane (1.75 g, 6.88 mmol), potassium acetate (1.93 g, 19.7 mmol) and 1,2-dimethoxyethane (40 mL) was purged with argon. Then, 1,1′-bis(diphenylphosphino)ferrocenepalladium (II) dichloride dichloromethane adduct (0.535 g, 0.655 mmol) was added, and the mixture was purged with argon again. The mixture was stirred at 90° C. overnight. After cooled to room temperature, the mixture was filtered, and the filtrate was concentrated under reduced pressure. The residue was purified by column chromatography (Purif, silica gel, hexane to 70:30 hexane/EtOAc) to afford the title compound (571 mg, 25%) as a colorless oil:

Workup

customwas purged with argon
customthe mixture was purged with argon again
temperatureAfter cooled to room temperature
filtrationthe mixture was filtered
concentrationthe filtrate was concentrated under reduced pressure
customThe residue was purified by column chromatography (Purif, silica gel, hexane to 70:30 hexane/EtOAc)

Sources & evidence

ORD record: ord-823b86513d974a7690a293db01e594fe
Source dataset: uspto-grants-2014_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08691828B2

Reaction notes

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