Potassium Phosphate, Tribasic → 5-(4-methylpyridin-3-yl)-1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazolo[3,4-b]pyridine-3-carbaldehyde

Participants

Reaction Conditions

Reaction Steps

To a heterogeneous solution of 5-bromo-1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazolo[3,4-b]pyridine-3-carbaldehyde (XI) (0.21 g, 0.67 mmol) and K3PO4 (0.212 g, 1 mmol) in DMF (5 mL) and water (0.5 mL) was added 4-methyl-pyridine-3-boronic acid (LVI) (0.101 g, 0.74 mmol). The solution was purged with nitrogen by using nitrogen/vacuum cycle (3×). Pd(PPh3)4 (23 mg, 0.02 mmol) was added to the solution and again purged with nitrogen. The solution was heated at 90° C. for 4 h under nitrogen. The solution was filtered through a pad of Celite while it was still hot. The Celite was washed with DCM (3×). The combined filtrate was concentrated under vacuum. The residue was dissolved in DCM, and washed subsequently with saturated NaHCO3 solution and brine. The organic layer was dried over MgSO4, filtered and concentrated under reduced pressure to produce 5-(4-methylpyridin-3-yl)-1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazolo[3,4-b]pyridine-3-carbaldehyde (LVII). The crude product was used directly for step 2 without further purification. ESIMS found for C18H18N4O2 m/z 323.4 (M+H).

Provenance & Evidence