Trifluoroacetic acid → N-((1R,2S)-2-aminocyclohexyl)-2-(5-methoxy-1-methyl-1H-indazol-3-yl)-5H-pyrrolo[2,3-b]pyrazine-7-carboxamide

Participants

Reaction Conditions

Reaction Steps

To a pale yellow solution of N-((1R,2S)-2-aminocyclohexyl)-2-(5-methoxy-1-methyl-1H-indazol-3-yl)-5-((2-(trimethylsilyl)ethoxy)methyl)-5H-pyrrolo[2,3-b]pyrazine-7-carboxamide (21 mg, 38.2 μmol) in dichloromethane (3.00 mL) was added TFA (1.48 g, 1.00 mL, 13.0 mmol, Eq: 340), the reaction mixture turned dark red and was stirred at 25° C. overnight then concentrated. The residue was re-dissolved in 5 mL of a solution of (dichloromethane/MeOH/ammonium hydroxide; 60:10:1) and stirred at 25° C. for 3 h, then evaporated to a light yellow solid, dissolved in dichloromethane (added few drops MeOH and heating) and purified by chromatography (spherical silica 20-45 μm, 23 g, Versaflash Supelco) eluting with 0 to 10% over 15 min (MeOH containing 10% ammonium hydroxide)/dichloromethane. The pure product dissolved in hot MeOH and allowed to stand overnight for solid formation. The solid was separated by decantation and dried under high vacuum to give N-((1R,2S)-2-aminocyclohexyl)-2-(5-methoxy-1-methyl-1H-indazol-3-yl)-5H-pyrrolo[2,3-b]pyrazine-7-carboxamide (9 mg, 21.5 μmol, 56.2%) as a white solid. MS (M+H)+=420 (100% purity); 1H NMR (DMSO-d6) δ: 9.02 (s, 1H), 8.34-8.45 (m, 2H), 8.07 (d, J=2.3 Hz, 1H), 7.69 (d, J=9.4 Hz, 1H), 7.29 (dd, J=9.3, 2.5 Hz, 1H), 4.14 (s, 3H), 4.01-4.10 (m, 1H), 3.88 (s, 3H), 3.05 (d, J=3.8 Hz, 1H), 1.50-1.82 (m, 6H), 1.40 (br. s., 2H).

Provenance & Evidence