A mixture of 3-bromo-N-butylimidazo[1,2-b]pyridazin-6-amine (100 mg, 0.37 mmol), (1H-pyrazol-4-yl)boronic acid (90 mg, 0.45 mmol), dichloro-bis(triphenylphosphino) palladium (II) (15 mg, 0.021 mmol), potassium phosphate (80 mg, 0.56 mmol), acetonitrile (1.5 mL) and H2O (0.5 mL) was heated in a sealed conical vessel at 160° C. for 1000 s by microwave irradiation. The organic layer was separated and the aqueous layer was extracted with ethyl acetate (2 mL). The combined organic layers were concentrated under reduced pressure to afford an oil that was purified by reverse phase HPLC to afford butyl-[3-(1H-pyrazol-4-yl)-imidazo[1,2-b]pyridazin-6-yl]-amine (60 mg, 62%) as a white solid: 1H NMR (400 MHz, METHANOL-d4) δ ppm 7.67 (s, 1H), 7.59 (d, J=9.6 Hz, 1H), 6.67 (d, J=9.6 Hz, 1H), 3.44 (t, J=7.1 Hz, 1H), 1.70-1.80 (m, 1H), 1.46-1.59 (m, 1H), 1.03 (t, J=7.3 Hz, 1H); LCMS (ESI) m/e 257.3 [(M+H)+, calcd for C13H17N6 257.1].
