To a stirred solution of 5-(5-phenyl-4-((pyridin-2-ylmethyl)amino)pyrrolo[2,1-f][1,2,4]triazin-2-yl)nicotinonitrile (50.0 mg, 0.124 mmol) in dioxane (5 mL)/MeOH (2 mL) was added KOH (34.8 mg, 0.620 mmol) dissolved in water (2 mL) in a pressure tube. The contents were heated at 95° C. for 12 h. The reaction mixture was allowed to cool and concentrated under reduced pressure to give a white solid. The solid was dissolved in CHCl3 and washed with 1.5 N HCl (5 mL) and the organic layer was separated and dried over anhydrous Na2SO4, filtered and concentrated to give 5-(5-phenyl-4-((pyridin-2-ylmethyl)amino)pyrrolo[2,1-f][1,2,4]triazin-2-yl)nicotinic acid (24.0 mg, 49.0%) as an off-white solid. LCMS Condition B-23: retention time 1.64, [M+1]=423.2. HPLC Condition B-1: retention time 5.80 min, purity 98.80%. 1H NMR (400 MHz, DMSO-d6) δ ppm 4.94 (d, J=4.4 Hz, 2H), 6.83 (d, J=2.8 Hz, 1H), 7.21-7.52 (m, 8H), 7.89 (t, J=1.7 Hz, 1H), 7.96 (d, J=2.8 Hz, 1H), 8.38 (br s, 1H), 8.98 (s, 1H), 9.19 (s, 1H), 9.52 (s, 1H).
