2-(Trifluoromethoxy)phenylboronic Acid (contains varying amounts of Anhydride) → 5-bromo-3-(2-trifluoromethoxy-phenyl)-1-(2-trimethylsilanyl-ethoxymethyl)-1H-pyrazolo[3,4-b]pyridine

Participants

Reaction Conditions

Reaction Steps

A mixture of 5-bromo-3-iodo-1-(2-trimethylsilanyl-ethoxymethyl)-1H-pyrazolo[3,4-b]pyridine (3.5 g, 7.7 mmol), 2-trifluoromethoxyphenylboronic acid (2.2 g, 7.7 mmol), dichloro[1,1′bis(diphenyl-phosphino)ferrocene]palladium(II) dichloromethane adduct (284 mg, 0.4 mmol) in THF/Acetonitrile/saturated NaHCO3 (25 ml/25 ml/30 ml) was stirred at 60° C. for 4 hours. The mixture was allowed to cool down to room temperature and then extracted with ethyl acetate (3×). The combined organic layers were washed with brine, dried over Na2SO4, decanted, and concentrated to dryness. Silica chromatography of the crude using a gradient of ethyl acetate and hexane afforded 5-bromo-3-(2-trifluoromethoxy-phenyl)-1-(2-trimethylsilanyl-ethoxymethyl)-1H-pyrazolo[3,4-b]pyridine (2.2 g, 59% yield). 1H NMR (500 MHz, DMSO-d6) δ 0.02 (s, 9H), 0.94 (m, 2H), 3.77 (m, 2H), 6.00 (s, 2H), 7.75 (m, 2H), 7.80 (d, 1H), 8.01 (d, 1H), 8.66 (s, 1H), 8.91 (s, 1H). MS: m/z 489.1 (M+H+).

Provenance & Evidence