Pyridine → 1-(3-((2,2-difluoroethyl)amino)-2-(4-(2,4-difluorophenoxy)piperidin-1-yl)-7,8-dihydropyrido[3,4-b]pyrazin-6(5H)-yl)ethan-1-one

Participants

Reaction Conditions

Reaction Steps

A solution of N-(2,2-difluoroethyl)-2-(4-(2,4-difluorophenoxyl)piperidin-1-yl)-5,6,7,8-tetrahydropyrido[3,4-b]pyrazin-3-amine TFA salt (114 mg, 0.211 mmol) in DCM (2.11 mL) at 0° C. was treated with pyridine (0.051 mL, 0.63 mmol) and acetic anhydride (0.040 mL, 0.42 mmol). The reaction mixture was stirred for 30 min at 0° C. The reaction mixture was concentrated under reduced pressure. The residue was taken up in MeOH, filtered, and purified by HPLC Method B, using a 40% to 70% ACN gradient to give the title compound, as a TFA salt, as a yellow solid (39.7 mg, 32.3%). 1H NMR (500 MHz, methanol-d4, mixture of rotamers) δ ppm 1.96 (m, 2H), 2.12 (m, 2H), 2.18 (s, 1.3H), 2.20 (s, 1.7H), 2.73 (t, J=5.9 Hz, 0.8H), 2.83 (t, J=5.9 Hz, 1.2H), 3.01 (m, 2H), 3.39 (m, 2H), 3.80 (m, 4H), 4.45 (dt, J=7.0, 3.6 Hz, 1H), 4.57 (app d, 2H), 6.05 (m, 1H), 6.86 (m, 1H), 6.96 (ddd, J=11.2, 8.5, 3.2 Hz, 1H), 7.15 (td, J=9.2, 5.6 Hz, 1H); ESI-MS m/z [M+H]+ 468.4.

Provenance & Evidence