Formaldehyde → Trifluoroacetic acid

Participants

Reaction Steps

Sodium triacetoxyborohydride (15.3 mg, 0.072 mmol) was added to a mixture of DIPEA (9.4 mg, 0.072 mmol), 3-(4-((2,4-difluorophenyl)fluoromethyl)piperidin-1-yl)-N-isopropyl-5,6,7,8-tetrahydropyrido[3,4-b]pyrazin-2-amine TFA salt (19.3 mg, 0.036 mmol) and formaldehyde (3 μL, 0.036 mmol) in MeOH (360 μL) at rt. After 30 min, the mixture was purified by HPLC Method A to give the title compound as a TFA salt (19.3 mg, 97%) as a yellow film. 1H NMR (400 MHz, methanol-d4) δ ppm 1.24 (dd, J=6.4, 2.2 Hz, 6H), 1.40-1.48 (m, 1H), 1.53-1.74 (m, 2H), 1.96-2.14 (m, 2H), 2.60-2.73 (m, 2H), 2.93-3.06 (br m, 2H), 3.06 (s, 3H), 3.39-3.54 (m, 3H), 3.69-3.81 (m, 1H), 4.18 (dt, J=13.1, 6.4 Hz, 2H), 4.16-4.36 (br m, 1H), 5.52 (dd, J=46.2, 7.6 Hz, 1H), 6.97-7.08 (m, 2H), 7.47-7.54 (m, 1H); ESI-MS m/z [M+H]+ 434.4.

Provenance & Evidence