To a stirred solution of 4-(benzylamino)-5-phenylpyrrolo[2,1-f][1,2,4]triazine-2-carbonitrile (0.100 g, 0.307 mmol) dissolved in tert-butanol (15.0 mL, 157 mmol) and water (15 mL) was added potassium tert-butoxide (0.138 g, 1.23 mmol). The reaction mixture was heated in a pressure tube to 95° C. for 16 h and concentrated under reduced pressure. To the resulting residue, was added water (100 mL) and the aqueous solution was neutralized with dilute HCl to pH 7. The solid precipitated, was filtered and further purified by preparative HPLC (Condition B-74 as described in general methods) to afford 4-(benzylamino)-5-phenylpyrrolo[2,1-f][1,2,4]triazine-2-carboxylic acid (30.0 mg, 28.3%). LCMS Condition B-15: retention time 1.66 min, [M+1]=345.2. HPLC Condition B-1: retention time 14.64 min, Purity 99.30%. 1H NMR (400 MHz, DMSO-d6) δ ppm 4.71 (s, 2H), 6.29 (br s, 1H), 6.77 (d, J=2.8 Hz, 1H), 7.24-7.48 (m, 10H), 7.77 (d, J=2.8 Hz, 1H).
