1-Methylpiperazine (140 μl, 1.27 mmol) was added to 2-chloro-N-[4-[1-(3-(trifluoromethyl)-[1,2,4]triazolo[4,3-b]pyridazin-6-yl]piperidin-4-yl]phenyl]acetamide (139 mg, 0.317 mmol) and sodium iodide (10 mg, 0.063 mmol) in a mixture of THF (2 mL) and DMA (0.5 mL). The resulting solution was heated at 60° C. for 2 hours, then cooled and evaporated to give the crude product which was purified by preparative HPLC (Waters XBridge Prep C18 OBD column, 5μ silica, 19 mm diameter, 100 mm length), using decreasingly polar mixtures of water (containing 1% ammonia) and MeCN as eluents. Fractions containing the desired compound were evaporated to dryness to give 2-(4-methylpiperazin-1-yl)-N-[4-[1-[3-(trifluoromethyl)[1,2,4]triazolo[4,3-b]pyridazin-6-yl]piperidin-4-yl]phenyl]acetamide (111 mg, 70%) as a solid.
