To a solution of 5-chloro-3-(5-fluoro-4-methylsulfonyl-pyrimidin-2-yl)-1-(p-tolylsulfonyl)pyrrolo[2,3-b]pyridine, 1a, (3.5 g, 7.5 mmol) and tert-butyl (3S)-3-aminopiperidine-1-carboxylate (1.8 g, 9.0 mmol) in DMF (32 mL) was added diisopropylethylamine (2.6 mL, 15.1 mmol). The reaction mixture was heated at 90° C. for 75 minutes. The mixture was cooled to room temp and diluted into aqueous saturated NH4Cl solution and extracted with EtOAc. The organic phase was washed with brine (3 times), dried (MgSO4), filtered and concentrated under vacuo. The resulting residue was purified via silica gel chromatography (0%-10% MeOH/CH2Cl2) to afford the desired product 1b as a white solid.
