In an appropriate sized vial the trifluoroacetic acid salt of (R)-4-((R)-1-((3-cyclopropyl-6-(4-(piperazin-1-yl)phenyl)-3H-imidazo[4,5-c]pyridin-4-yl)oxy)ethyl)pyrrolidin-2-one 3.42 (25 mg, 0.044 mmol) and triethylamine (27 mg, 0.27 mmol) were dissolved in DCM (1.5 mL). To this mixture 2,2-difluoroethyl trifluoromethanesulfonate (11 mg, 0.051 mmol) was added and mixture was stirred at room temperature for 30 min. The solution was concentrated under reduced pressure and the residue was purified via prep HPLC (2-65% acetonitrile in water, 0.1% trifluoroacteic acid) to isolate (R)-4-((R)-1-((3-cyclopropyl-6-(4-(4-(2,2-difluoroethyl)piperazin-1-yl)phenyl)-3H-imidazo[4,5-c]pyridin-4-yl)oxy)ethyl)pyrrolidin-2-one 3.46 as a trifluoroacetic acid salt.
