Cesium carbonate → 4-[3-[(E)-2-(4-chloro-phenyl)-vinyl]-6-(4-hydroxy-phenyl)-1-(tetrahydro-pyran-2-yl)-1H-pyrazolo[3,4-b]pyridine-4-carbonyl]-piperazine-1-carboxylic acid tert-butyl ester

Participants

Reaction Steps

To a solution of 4-[6-chloro-3-[(E)-2-(4-chloro-phenyl)-vinyl]-1-(tetrahydro-pyran-2-yl)-1H-pyrazolo[3,4-b]pyridine-4-carbonyl]-piperazine-1-carboxylic acid tert-butyl ester (1.5 g, 2.56 mmol) in dioxane (38 ml) were added 4-hydroxyphenylboronic acid (0.39 g, 2.81 mmol) and an aqueous solution of cesium carbonate (0.3M, 4.6 mmol). The resulting solution was degassed using argon, tetrakis(triphenylphosphine)palladium (0.14 g, 0.13 mmol) was then added and the reaction mixture was refluxed for 3 hours. Solvents were removed under vacuum. The resulting crude mixture was submitted to a silica gel column chromatography using a gradient of ethyl acetate (0-45%) in cyclohexane to give the title compound (1.32 g, 80%) as a white solid.

Provenance & Evidence