To a light brown solution of 2-(6-fluoro-1-methyl-1H-indazol-3-yl)-5-(2-trimethylsilanylethoxymethyl)-5H-pyrrolo[2,3-b]pyrazine-7-carboxylic acid [1-(3-bromo-phenyl)-cyclobutyl]-amide (50 mg, 0.077 mmol) in dichloromethane (3 mL) was added an excess of TFA (1.2 mL, 15.4 mmol) at room temperature under nitrogen atmosphere. The resulting light brown solution was stirred for 4 h at which time TLC analysis (EA, Rf=0.35) indicated the absence of starting material. Then, the solvent was removed under vacuum and the residue was azeotroped with toluene to obtain a light brown solid. Then, this solid was treated with an excess of triethylamine (1.07 mL, 7.7 mmol) in methanol (3 mL) at room temperature under nitrogen atmosphere. The resulting suspension was stirred for 15 h and then the solvent was removed under vacuum. The residue was triturated with acetonitrile and the solids were collected by filtration and washed with acetonitrile. After drying in air, 15 mg (38%) of the 2-(6-fluoro-1-methyl-1H-indazol-3-yl)-5H-pyrrolo[2,3-b]pyrazine-7-carboxylic acid [1-(3-bromo-phenyl)-cyclobutyl]-amide was isolated as a light yellow solid. LC-MS (M+H)+=519; 1H NMR (300 MHz, DMSO-d6) δ: 12.80 (br. s., 1H), 9.10 (s, 1H), 8.77 (s, 1H), 8.55 (dd, J=8.8, 5.5 Hz, 1H), 8.36 (s, 1H), 7.64-7.80 (m, 2H), 7.57 (d, J=7.8 Hz, 1H), 7.41 (d, J=7.8 Hz, 1H), 7.23-7.35 (m, 1H), 7.15 (t, J=8.2 Hz, 1H), 4.15 (s, 3H), 2.56-2.81 (m, 4H), 2.19 (d, J=8.5 Hz, 1H), 1.96 (d, J=8.3 Hz, 1H).
