Cesium carbonate → 4-[4-Bromo-5-(1-{[2-(trimethylsilyl)ethoxy]methyl}-1H-1,2,4-triazol-3-yl)-2-thienyl]pyridine

Participants

Reaction Conditions

Reaction Steps

A mixture of 3-(3-bromo-5-iodo-2-thienyl)-1-{[2-(trimethylsilyl)ethoxy]methyl}-1H-1,2,4-triazole (653.0 mg, 1.34 mmol), pyridine-4-boronic acid (248 mg, 2.02 mmol), [1,1′-bis(diphenylphosphino)ferrocene]palladium(II)dichloride (55.2 mg, 0.067 mmol) and cesium carbonate (1.80 g, 5.37 mmol) in 1,4-dioxane (8.40 mL, 107 mmol) and water (1.2 mL, 67.1 mmol) was heated at 110° C. under an atmosphere of argon overnight. Water (3 mL) and EtOAc (3 mL) were added, the organic layer was separated, washed with brine, dried over MgSO4, filtered, concentrated and the obtained residue was purified by column chromatography (SiO2, elution with 0-10% MeOH in DCM) to give the title compound as a white solid (438 mg, 74.6%). LCMS: (FA) ES+, 438, 440. 1H NMR (400 MHz, d6-DMSO) δ: 8.87 (s, 1H), 8.62-8.64 (dd, J=1.5 Hz, 2H), 7.98 (s, 1H), 7.30-7.75 (dd, J=1.5, 2H), 5.58-5.59 (s, br, 2H), 3.40-3.69 (m, 2H), 0.840-0.890 (m, 2H), −0.04 (s, 9H).

Provenance & Evidence