To a microwave vial was added tert-butyl{1-[4-(3-hydroxy-9-phenyl[1,2,4]triazolo[3,4-f]-1,6-naphthyridin-8-yl)phenyl]cyclobutyl}carbamate (1-5e) (113 mg, 0.223 mmol), silver oxide (310 mg, 1.336 mmol), bromoethane (0.062 mL, 0.826 mmol), and finally NMP (1 mL). The reaction mixture was then heated to 80° C. under microwave irradiation for 10 minutes. Upon completion the reaction mixture was filtered and then purified by reverse phase column chromatography (Sunfire C18) eluting with 20 to 100% acetonitrile/(0.1% TFA/water) gradient. The appropriate fractions were then combined, suspended in ethyl acetate, washed with a saturated solution of sodium bicarbonate, water and brine, dried over sodium sulfate, filtered and concentrated in vacuo to give tert-butyl{1-[4-(3-ethoxy-9-phenyl[1,2,4]triazolo[3,4-f]-1,6-naphthyridin-8-yl)phenyl]cyclobutyl}carbamate (9-1) as a tan solid. MS (M+H)+: observed=536.4, calculated=536.64.
