Pyridine → Trifluoroacetic acid

Participants

Reaction Steps

Acetic anhydride (5 μL, 0.058 mmol) was added to a solution of 3-(4-(2,4-difluorophenoxyl)piperidin-1-yl)-N-isopropyl-5,6,7,8-tetrahydropyrido[3,4-b]pyrazin-2-amine TFA salt (15.1 mg, 0.029 mmol) and pyridine (7 μL, 0.088 mmol) in DCM (290 μL) at rt. After 1 h, the mixture was purified by HPLC Method A to give the title compound as a TFA salt (12.7 mg, 78%) as a yellow film. 1H NMR (400 MHz, methanol-d4, mixture of rotamers) δ ppm 1.33 (d, J=6.6 Hz, 6H), 1.91-2.02 (m, 2H), 2.09-2.18 (m, 2H), 2.19 (s, 1.4H), 2.21 (s, 1.6H), 2.77-2.83 (m, 0.9H), 2.88-2.94 (m, 1.1H), 3.12 (td, J=8.5, 4.0 Hz, 2H), 3.43-3.51 (m, 2H), 3.80-3.85 (m, 1.1H), 3.86-3.91 (m, 0.9H), 4.10-4.18 (m, 1H), 4.47-4.54 (m, 1H), 4.55 (br s, 2H), 6.85-6.92 (m, 1H), 6.99 (ddd, J=11.4, 8.6, 3.0 Hz, 1H), 7.18 (td, J=9.2, 5.6 Hz, 1H); ESI-MS m/z [M+H]+ 446.4.

Provenance & Evidence