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

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Reaction Conditions

Reaction Steps

In a 250 ml round bottom flask were charged 4-[6-chloro-1-(tetrahydro-pyran-2-yl)-3-vinyl-1H-pyrazolo[3,4-b]pyridine-4-carbonyl]-piperazine-1-carboxylic acid tert-butyl ester (1.2 g, 2.52 mmol), (3-iodo-benzyl)-dimethyl-amine (1.64 g, 6.3 mmol), tetrabutylammonium bromide (0.32 g, 1 mmol), sodium hydrogen carbonate (0.53 g, 6.3 mmol) and anhydrous dimethylformamide (42 ml). The mixture was degassed during 10 minutes using argon, palladium acetate (0.05 g, 0.25 mmol) was then added. The resulting solution was heated at 100° C. under argon overnight. Dimethylformamide was eliminated under vacuum, dichloromethane and water were added to the residue, after extraction the organic layer was dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to give the crude product. Further purification on a silica gel column chromatography using a gradient of methanol (0-5%) in dichloromethane afforded the title compound as brown solid (0.44 g, 29%).

Provenance & Evidence