Pyridine → Trifluoroacetic acid

Participants

Reaction Steps

A mixture of N-cyclobutyl-2-(4-(2-fluoro-4-methoxyphenoxy)piperidin-1-yl)-5,6,7,8-tetrahydropyrido[3,4-b]pyrazin-3-amine TFA salt (10.1 mg, 0.019 mmol), acetic anhydride (3.8 mg, 0.037 mmol) and pyridine (4 mg, 0.056 mmol) in DCM (190 μL) was stirred at room temperature for 30 min. The mixture was purified by HPLC Method A to give the title compound as a TFA salt (9.7 mg, 89%) as a yellow film. 1H NMR (400 MHz, methanol-d4, mixture of rotamers) δ ppm 1.78-1.87 (m, 2H), 1.91-2.01 (m, 2H), 2.03-2.16 (m, 4H), 2.19 (s, 1.2H), 2.21 (s, 1.8H), 2.38-2.50 (m, 2H), 2.70-2.76 (m, 0.8H), 2.80-2.87 (m, 1.2H), 3.00-3.11 (m, 2H), 3.40-3.50 (m, 2H), 3.76 (s, 3H), 3.79-3.83 (m, 1.2H), 3.84-3.88 (m, 0.8H), 4.34-4.48 (m, 2H), 4.57 (s, 0.8H), 4.61 (s, 1.2H), 6.64-6.69 (m, 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]+ 470.4.

Provenance & Evidence