Reaction Steps
A 1-dram vial equipped with a stir bar and septum cap was charged with dioxane (0.767 mL) and the solvent was degassed by bubbling argon through it with vigorous stirring for 10 min. 5A (0.050 g, 0.153 mmol), 6-aminonicotinonitrile (0.022 g, 0.184 mmol), cesium carbonate (0.100 g, 0.307 mmol), Xantphos (4.44 mg, 7.67 μmol), and Pd2(dba)3 (7.02 mg, 7.67 μmol) were added to the degassed solvent in one portion, and the resulting dark brown suspension was pump/purged with argon three times. The mixture was then heated to 100° C. 24 h. The suspension was cooled to room temperature and then triturated with water resulting in an olive green suspension, which was carefully filtered through a medium-porosity frit. The solid contains impure desired product, while the filtrate appears to contain only SM. The solid was collected, suspended in THF, and azeotroped with PhMe to remove residual water and MeOH. The crude solid was suspended in NMP (0.767 mL) and (trans)-cyclohexane-1,4-diamine (0.210 g, 1.840 mmol) was added. The resulting brown suspension was irradiated in a CEM Discover 300 W microwave at 110° C. for 20 min. Upon cooling, the mixture was diluted with DMF and purified via preparatory HPLC using a YMC ODS C-18 column (30×250 mm) 0%-100% B. Solvent B: (90% MeOH, 10% H2O, 0.1% TFA). Solvent A: (10% MeOH, 90% H2O, 0.1% TFA). Gradient, start % B=0, final % B=100, gradient time 60 min, flow rate 25 mL/min. Rt=48.454 min. The appropriate fractions were concentrated and lyophilized overnight, and 6-((trans)-4-aminocyclohexylamino)-8-(5-cyanopyridin-2-ylamino)-N-(3-fluoropyridin-4-yl)imidazo[1,2-b]pyridazine-3-carboxamide (0.006 g, 6.11 μmol, 3.99% yield) was obtained as a light tan lyophile. HPLC: Rt=3.445 min. YMC S5 ODS-A column (4.6×50 mm) 0%-100% B. Solvent B: (90% MeOH, 10% H2O, 0.2% H3PO4). Solvent A: (10% MeOH, 90% H2O, 0.2% H3PO4). Gradient, start % B=0, final % B=100, gradient time 4 min, hold at 100% 1 min, flow rate 4 mL/min. MS: [M+H]=487.1. 1H NMR (400 MHz, DMSO-D6) δ ppm 11.16 (1H, s), 10.48 (1H, s), 8.75 (1H, d, J=2.01 Hz), 8.65 (1H, d, J=2.52 Hz), 8.44-8.50 (1H, m), 8.40-8.44 (1H, m), 8.17 (1H, d, J=2.27 Hz), 8.13-8.16 (1H, m), 7.97 (1H, s), 7.81 (2H, s), 7.65 (1H, d, J=8.81 Hz), 7.45 (1H, s), 3.83 (1H, s), 3.07 (1H, s), 2.12 (2H, s), 1.95 (2H, d, J=1.01 Hz), 1.26-1.47 (4H, m).
