Trifluoroacetic acid → N-isopropyl-2-(1-methyl-1,4,5,6-tetrahydrocyclopenta[c]pyrazol-3-yl)-5H-pyrrolo[2,3-b]pyrazine-7-carboxamide

Participants

Reaction Steps

To a solution of N-isopropyl-2-(1-methyl-1,4,5,6-tetrahydrocyclopenta[c]pyrazol-3-yl)-5-((2-(trimethylsilyl)ethoxy)methyl)-5H-pyrrolo[2,3-b]pyrazine-7-carboxamide (68 mg, 150 μmol) in dichloromethane (5 mL) was added TFA (1.48 g, 1.00 mL, 13.0 mmol) and the reaction mixture stirred for 15 h 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 and purified by chromatography (40 g column, 50 μm from Analogix, 0 to 5% MeOH containing 10% ammonium hydroxide in dichloromethane). The pure product was suspended in dichloromethane and cyclohexane added to promote solid formation, which was separated by decantation and dried under high vacuum to give N-isopropyl-2-(1-methyl-1,4,5,6-tetrahydrocyclopenta[c]pyrazol-3-yl)-5H-pyrrolo[2,3-b]pyrazine-7-carboxamide (45 mg, 139 mmol, 93%) as a white solid. MS (M+H)+=325; 1H NMR (DMSO-d6) δ: 12.68 (br. s., 1H), 8.87 (s, 1H), 8.31 (s, 1H), 8.00 (d, J=7.9 Hz, 1H), 4.02-4.46 (m, 1H), 3.79 (s, 3H), 2.92 (t, J=6.4 Hz, 2H), 2.73 (t, J=6.4 Hz, 2H), 2.60 (t, J=6.4 Hz, 2H), 1.24 (d, J=6.4 Hz, 6H).

Provenance & Evidence