Methyl chloroformate → Methyl 2-(4-(2,4-difluorophenoxy)piperidin-1-yl)-3-(isopropylamino)-7,8-dihydropyrido[3,4-b]pyrazine-6(5H)-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of 2-(4-(2,4-difluorophenoxyl)piperidin-1-yl)-N-isopropyl-5,6,7,8-tetrahydropyrido[3,4-b]pyrazin-3-amine (45.6 mg, 0.113 mmol) and triethylamine (0.039 mL, 0.283 mmol) in DCM (0.75 mL) was added methyl carbonochloridate (0.013 mL, 0.170 mmol) at 0° C. The reaction mixture was stirred at 0° C. for 1 hr, warmed to 23° C., and concentrated via rotary evaporation. The resulting crude material was partitioned between EtOAc and H2O. The organic phase was washed with brine, dried over Na2SO4, filtered, rinsed with EtOAc, and concentrated via rotary evaporation. The crude material was dissolved in toluene (0.5 mL) and purified via medium pressure chromatography using a 2% to 80% gradient eluant of EtOAc in heptane on a 12 g silica gel column (Single Step™) to give the title compound (48.7 mg, 93%) as a white foam. 1H NMR (500 MHz, DMSO-d6) δ ppm 1.17-1.19 (m, 6H), 1.80-1.94 (m, 2H), 2.06 (ddd, J=9.5, 5.9, 3.2 Hz, 2H), 2.64 (t, J=5.9 Hz, 2H), 2.82-2.94 (m, 2H), 3.19-3.31 (m, 2H), 3.64 (s, 3H), 3.64-3.69 (m, 2H), 4.07-4.17 (m, 1H), 4.35 (br s, 2H), 4.51 (tt, J=8.1, 3.9 Hz, 1H), 5.53 (d, J=8.3 Hz, 1H), 7.01 (dddd, J=9.3, 8.1, 3.2, 1.5 Hz, 1H), 7.26-7.35 (m, 2H); ESI-MS m/z [M+H]+ 461.9.

Provenance & Evidence