Hydrochloric Acid → 2-[4-(1-aminocyclobutyl)phenyl]-N-cyclopropyl-9-fluoro-3-phenylpyrimido[1,2-b]indazol-4-amine

720 mg (1.3 mmol) Crude {1-[4-(9-fluoro-4-cyclopropylamino-3-phenyl-pyrimido[1,2-b]indazol-2-yl)phenyl]cyclobutyl}carbamic acid tert-butyl ester, described in step 2, were dissolved in 36 mL dioxane. After dropwise addition of 36 mL of a 4 M hydrogen chloride in dioxane the reaction mixture was stirred for five hours at room temperature. The reaction mixture was evaporated to dryness. Saturated aqueous sodium bicarbonate solution was added and the reaction mixture was extracted three times with ethyl acetate. The combined organic extracts were washed with brine and dried. After evaporation of the solvent the residue was purified by HPLC to yield 44.3 mg of the desired compound which was 90% pure.