To a mixture of tert-butyl {1-[4-(6-methyl-3-phenylimidazo[1,2-b]pyridazin-2-yl)phenyl]-cyclobutyl}carbamate that was prepared in a manner analgous to that described for Intermediate Example Int-1 (200 mg, 0.440 mmol, 1.0 eq) in DCM (2.2 mL) and methanol (1.8 mL) was added a solution of 4 M hydrogen chloride in dioxane (2.2 mL, 8.80 mmol, 20.0 eq) and the mixture was stirred for overnight at rt. The mixture was poured onto ice, made alkaline with aqueous sodium hydroxide (2 N) and extracted with DCM. The combined organic phases were washed with brine, dried and concentrated in vacuo. Purification was achieved by crystallization from diisopropyl ether. The resulting solid was filtered and dried under high vacuum overnight to give 130 mg (83% yield) of the title compound.
