In a 125 mL round-bottomed flask, 2-(6-fluoro-1-methyl-1H-indazol-3-yl)-5-(2-trimethylsilanyl-ethoxymethyl)-5H-pyrrolo[2,3-b]pyrazine-7-carboxylic acid (3-hydroxy-1,3-dimethyl-butyl)-amide (25 mg, 0.046 mmol), cesium fluoride (70 mg, 0.46 mmol) and 18-crown-6 (12 mg, 0.046 mmol) were combined with acetonitrile to give an off-white suspension. The reaction was stirred at reflux for 72 h. A large excess of CsF and 18-crown-6 was added and the reaction was heated for an additional 24 h. The reaction mixture was diluted with ethyl acetate and washed with water. The organic layer was dried over Na2SO4 and concentrated. The crude material was suspended in water and collected by filtration then triturated with 1:2 dichloromethane/heptane to afford 4 mg (21%) of 2-(6-fluoro-1-methyl-1H-indazol-3-yl)-5H-pyrrolo[2,3-b]pyrazine-7-carboxylic acid (3-hydroxy-1,3-dimethyl-butyl)-amide as a yellow solid. MS: [M+Na]+=433, 1H NMR (300 MHz, DMSO-d6) δ: 12.83 (br. s., 1H), 9.10 (s, 1H), 8.57 (dd, J=8.9, 5.5 Hz, 1H), 8.41 (d, J=2.3 Hz, 1H), 8.15 (d, J=8.3 Hz, 1H), 7.71 (dd, J=9.8, 1.9 Hz, 1H), 7.20 (td, J=9.1, 2.3 Hz, 1H), 4.35 (s, 1H), 4.29-4.43 (m, 1H), 4.16 (s, 3H), 1.83 (dd, J=14.4, 7.9 Hz, 1H), 1.73 (dd, J=16.6, 4.9 Hz, 1H), 1.31 (d, J=6.4 Hz, 3H), 1.15 (s, 3H), 1.12 (s, 3H).
