Reaction Steps
(S)-3-(hydroxymethyl)-7,8,9,10-tetrahydro-5H-dipyrido[1,2-a:3′,2′-e]pyrazin-6(6aH)-one (330 mg, 1.415 mmol) was suspended in propionitrile (3.5 mL) and (cyanomethyl)trimethylphosphonium iodide (413.0 mg, 1.70 mmol) was added followed by N-ethyl-N-isopropylpropan-2-amine (741 ul, 4.2 mmol). To the stirred mixture was then added ethyl 6-(piperazin-1-yl)nicotinate (366 mg, 1.56 mmol). The reaction was heated to 90° C. with stirring for 16 h. The reaction was then cooled to room temperature, diluted with EtOH (8 ml) and water (1 mL), then filtered. The precipitate was filtered off and dried in vacuum to afford the title compound (567 mg, 89%) as a brown solid. 1H NMR (DMSO-d6) δ (ppm): 10.48 (s, 1H), 8.63 (d, J=2.0 Hz, 1H), 7.93 (dd, J=9.1, 2.3 Hz, 1H), 7.65 (d, J=1.8 Hz, 1H), 6.97 (d, J=2.0 Hz, 1H), 6.85 (d, J=9.1 Hz, 1H), 4.44-4.56 (m, 1H), 4.24 (q, J=7.1 Hz, 2H), 3.84 (dd, J=11.4, 2.8 Hz, 1H), 3.53-3.73 (m, 4H), 3.35 (s, 2H), 2.60 (td, J=12.6, 2.5 Hz, 1H), 2.41 (t, J=4.8 Hz, 4H), 2.05 (br. s., 1H), 1.85 (d, J=12.4 Hz, 1H), 1.64 (d, J=12.4 Hz, 1H), 1.34-1.57 (m, 3H), 1.28 (t, 3H) [M+H] calc'd for C24H30N6O3, 451; found, 451.
