Reaction Steps
To a solution of 6-((trans)-4-aminocyclohexylamino)-N-(3-fluoropyridin-4-yl)-8-((4-methoxybenzyl)(pyridin-2-yl)amino)imidazo[1,2-b]pyridazine-3-carboxamide 5C (41.5 mg, 0.051 mmol) and DIEA (0.045 mL, 0.256 mmol) in CH2Cl2 (1 mL) at room temperature was added dimethylcarbamic chloride (4.94 μL, 0.054 mmol), slowly, via syringe. The reaction was stirred overnight at room temperature. Volatiles were removed via a stream of nitrogen and TFA (0.5 mL) was added. The mixture was then heated at 60° C. in an oil bath for 4 h. The reaction was then cooled to room temperature and the TFA was removed under reduced pressure. The resulting crude material was diluted with 1 mL of THF 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=56.165 min. 6-((trans-4-((dimethylcarbamoyl)amino)cyclohexyl)amino)-N-(3-fluoro-4-pyridinyl)-8-(2-pyridinylamino)imidazo[1,2-b]pyridazine-3-carboxamide, 2TFA (18 mg, 45.2% yield) was obtained as a white foam. LC/MS, m/z 533.1 (M+1). HPLC Rt=4.200 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. 1H NMR (500 MHz, DMSO-d6) δ ppm 11.31 (1H, s), 9.82 (1 H, s), 8.73 (1H, d, J=2.47 Hz), 8.51 (1H, t, J=6.05 Hz), 8.44 (1H, d, J=5.22 Hz), 8.34 (1H, d, J=3.85 Hz), 8.12 (1H, s), 7.97 (1H, s), 7.68-7.80 (1H, m), 7.50 (1H, d, J=8.52 Hz), 7.17-7.26 (1H, m), 7.02 (1H, dd, J=6.74, 5.36 Hz), 5.84-5.93 (1H, m), 3.77-3.87 (1H, m), 3.40 (1H, d, J=6.05 Hz), 2.78 (6H, s), 2.06 (2H, s), 1.80 (2H, s), 1.34 (4H, d, J=12.10 Hz).
