Tetrabutylammonium Fluoride → 2-(5-hydroxy-1-methyl-1H-indazol-3-yl)-5H-pyrrolo[2,3-b]pyrazine-7-carboxylic acid isopropylamide

In a round-bottomed, 2-[5-(tert-butyl-dimethyl-silanyloxy)-1-methyl-1H-indazol-3-yl]-5H-pyrrolo[2,3-b]pyrazine-7-carboxylic acid isopropylamide (50 mg, 0.108 mmol) was suspended in THF (1.2 ml) and tetrabutylammonium fluoride (1.0 M in THF, 0.11 ml, 110 mmol) was added. The reaction mixture was stirred at room temperature for 1 h then quenched with water and diluted with ethyl acetate. The resulting suspension was filtered and the solid was washed with hot water and ethyl acetate then dried under high vacuum to provide 33 mg (83%) of 2-(5-hydroxy-1-methyl-1H-indazol-3-yl)-5H-pyrrolo[2,3-b]pyrazine-7-carboxylic acid isopropylamide as a yellow powder. MS: (M+Na)+=373; 1H NMR (DMSO-d6, 300 MHz): δ (ppm) 12.77 (br. s., 1H), 9.25 (s, 1H), 9.06 (s, 1H), 8.38 (s, 1H), 8.16 (d, J=7.6 Hz, 1H), 7.73 (d, J=1.9 Hz, 1H), 7.60 (d, J=9.1 Hz, 1H), 7.10 (dd, J=9.1, 2.3 Hz, 1H), 4.23 (dq, J=13.6, 6.7 Hz, 1H), 4.13 (s, 3H), 1.35 (d, J=6.8 Hz, 6H).