Formaldehyde → Trifluoroacetic acid

Participants

Reaction Steps

Sodium triacetoxyborohydride (22.3 mg, 0.105 mmol) was added to a mixture of DIPEA (18 μL, 0.105 mmol), 3-(4-(2-fluoro-4-methoxyphenoxy)piperidin-1-yl)-N-isopropyl-5,6,7,8-tetrahydropyrido[3,4-b]pyrazin-2-amine TFA salt (27.9 mg, 0.053 mmol) and formaldehyde (4 μL, 0.053 mmol) in MeOH (550 μL) at rt. After 30 min, the mixture was purified by HPLC Method A to give the title compound as a TFA salt (27.9 mg, 97%) as a yellow film. 1H NMR (400 MHz, methanol-d4) δ ppm 1.25 (d, J=6.3 Hz, 6H), 1.88-1.98 (m, 2H), 2.04-2.14 (m, 2H), 2.93-3.05 (m, 3H), 3.07 (br s, 4H), 3.33-3.40 (m, 2H), 3.41-3.69 (m, 2H), 3.75 (s, 3H), 4.15-4.32 (m, 3H), 4.32-4.39 (m, 1H), 6.66 (ddd, J=8.9, 3.0, 1.5 Hz, 1H), 6.73 (dd, J=12.8, 2.9 Hz, 1H), 7.07 (t, J=9.2 Hz, 1H); ESI-MS m/z [M+H]+ 430.4.

Provenance & Evidence