(+/−)2-((2-chloro-5-cyano-3-(6-fluoro-4-(oxetan-3-yl)-1,4-diazepan-1-yl)phenyl)amino)-4-(cyclopropyl(4-methoxybenzyl)amino)imidazo[2,1-f][1,2,4]triazine-7-carbonitrile (89 mg, 0.138 mmol) was taken up in DCE (1 mL) and anisole (0.076 mL, 0.692 mmol) was added, followed by TFA (0.640 mL, 8.30 mmol). The reaction was stirred at room temperature overnight. An additional 1 ml of TFA was added, and the reaction was stirred at room temperature for 4 h. The solvent was removed in vacuo and the material dissolved in MeOH. The material was loaded onto an SCX column (5 g, benzenesulfonic acid sorbent) and the column was flushed with MeOH, then 1:1 DCM/7N NH3/MeOH to obtain the product. The solvent was removed in vacuo and the crude material was purified by preparative HPLC. 2-((2-chloro-5-cyano-3-(6-fluoro-4-(oxetan-3-yl)-1,4-diazepan-1-yl)phenyl)amino)-4-(cyclopropyl amino)imidazo[2,1-f][1,2,4]triazine-7-carbonitrile (12 mg) was obtained as a yellow solid.
