Acetic Anhydride → Trifluoroacetic acid

Participants

Reaction Steps

A solution of N-(tert-butyl)-3-(4-(2,4-difluorophenoxyl)piperidin-1-yl)-5,6,7,8-tetrahydropyrido[3,4-b]pyrazin-2-amine TFA salt (16 mg, 0.030 mmol), acetic anhydride (5.7 μL, 0.060 mmol), and DIPEA (15.8 μL, 0.090 mmol) in DCM (151 μL) was stirred at room temperature overnight. The crude reaction mixture was diluted in DMF, filtered through a hydrophilic PTFE 0.45 μm filter (Millipore® Millex-LCR), and purified via HPLC Method A to give the title compound as a TFA salt (15 mg) as a clear oil. 1H NMR (400 MHz, methanol-d4, mixture of rotamers) δ ppm 1.48 (s, 9H), 1.87-1.98 (m, 2H), 2.07-2.17 (m, 2H), 2.19 (s, 1.3H), 2.21 (s, 1.7H), 2.74 (t, J=5.9 Hz, 0.9H), 2.84 (t, J=5.9 Hz, 1.1H), 2.97 (ddd, J=12.4, 8.6, 3.3 Hz, 2H), 3.33-3.37 (m, 2H), 3.80 (t, J=5.9 Hz, 1.1H), 3.85 (t, J=5.9 Hz, 0.9H), 4.43-4.51 (m, 1H), 4.53 (d, J=1.3 Hz, 2H), 6.88 (ddddd, J=9.1, 8.1, 2.9, 1.9, 0.8 Hz, 1H), 6.95-7.02 (m, 1H), 7.18 (td, J=9.2, 5.3 Hz, 1H); ESI-MS m/z [M+H]+ 460.4.

Provenance & Evidence