To a mixture of hydroxylamine hydrochloride (15.3 mg, 0.22 mmol) and Na2CO3 (28 mg, 0.26 mmol) in water (0.7 mL) was added a solution of 4-((3-(3-chlorophenyl)imidazo[1,2-b]pyridazin-6-yl)amino)cyclohexanone (50 mg, 0.147 mmol) in MeOH (0.5 mL) at 0° C. The resulting mixture was stirred at room temperature for 1 h. LCMS showed the reaction was complete. The mixture was poured into water and extracted with EtOAc (50 mL*3). The combined extracts were dried over Na2SO4, filtered and concentrated in vacuo. The residue was purified by prep-HPLC and then by SFC to give EX. 8-92 (10 mg, 19%) as a white solid.
