1-(4-Chlorophenyl)-N4,N4-dimethylbutane-1,4-diamine (Intermediate 57) (330 mg, 1.46 mmol) was added in one portion to 4-(tert-butoxycarbonylamino)-1-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)piperidine-4-carboxylic acid (Intermediate 1) (526 mg, 1.46 mmol) and DIPEA (0.763 mL, 4.37 mmol) in DMA (5 mL). O-(7-azabenzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate (609 mg, 1.60 mmol) was added and the resulting solution was stirred at 50° C. for 2 hours. The reaction mixture was diluted with EtOAc (25 mL), and washed sequentially with water (20 mL) and saturated brine (20 mL). The organic layer was dried over MgSO4, filtered and evaporated to afford crude product. The crude product was purified by flash silica chromatography, elution gradient 5 to 10% MeOH with ammonia in isohexane. Pure fractions were evaporated to dryness to afford tert-butyl 4-(1-(4-chlorophenyl)-4-(dimethylamino)butylcarbamoyl)-1-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)piperidin-4-ylcarbamate (423 mg, 51.0%) as a colourless gum. tert-Butyl 4-(1-(4-chlorophenyl)-4-(dimethylamino)butylcarbamoyl)-1-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)piperidin-4-ylcarbamate (423 mg, 0.74 mmol) was dissolved in DCM (5.00 mL) and TFA (1 mL) added. The reaction was stirred at ambient temperature for 2 hours. The crude product was purified by ion exchange chromatography, using an SCX column. The desired product was eluted from the column using 3.5N ammonia/MeOH and pure fractions were evaporated to dryness to afford crude product which was triturated with diethyl ether to afford 4-amino-N-(1-(4-chlorophenyl)-4-(dimethylamino)butyl)-1-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)piperidine-4-carboxamide (245 mg, 35.8%) as a white solid.
