Pyridine → Trifluoroacetic acid

Participants

Reaction Steps

Acetic anhydride (9 μL, 0.095 mmol) was added to a solution of 3-(4-(2-fluoro-4-methoxyphenoxy)piperidin-1-yl)-N-isopropyl-5,6,7,8-tetrahydropyrido[3,4-b]pyrazin-2-amine TFA salt (25.2 mg, 0.048 mmol) and pyridine (11.5 μL, 0.143 mmol) in DCM (500 μL) at rt. After 1 h, the mixture was purified by HPLC Method A to give the title compound as a TFA salt (25.2 mg, 93%) as a yellow film. 1H NMR (400 MHz, methanol-d4, mixture of rotamers) δ ppm 1.32 (d, J=6.6 Hz, 6H), 1.89-2.00 (m, 2H), 2.06-2.15 (m, 2H), 2.19 (s, 1.4H), 2.21 (s, 1.6H), 2.77-2.83 (m, 0.9H), 2.87-2.93 (m, 1.1H), 3.04-3.14 (m, 2H), 3.42-3.50 (m, 2H), 3.75 (s, 3H), 3.80-3.85 (m, 1.1H), 3.85-3.90 (m, 0.9H), 4.09-4.19 (m, 1H), 4.35-4.42 (m, 1H), 4.55 (br s, 2H), 6.67 (dt, J=9.0, 1.4 Hz, 1H), 6.74 (dd, J=12.8, 2.9 Hz, 1H), 7.08 (t, J=9.2 Hz, 1H); ESI-MS m/z [M+H]+ 458.4.

Provenance & Evidence