(S)-3-(hydroxymethyl)-6a,7,8,9-tetrahydropyrido[3,2-e]pyrrolo[1,2-a]pyrazin-6(5H)-one (100 mg, 0.456 mmol), 1-(4-fluoro-2-methylphenyl)piperazine dihydrochloride (122 mg, 0.456 mmol), (cyanomethyl)trimethylphosphonium iodide (166 mg, 0.684 mmol) and N,N-diisopropylethylamine (0.398 ml, 2.281 mmol) were suspended in propiononitrile (Volume: 1.370 ml) and heated in a closed vial at 90-120° C. for 4 h. The reaction mixture became a dark brown solution. It was cooled to room temperature, concentrated in vacuo, dissolved in DMSO (2 mL) and purified using HPLC (basic, 45-95% ACN in water, basic). The fractions were concentrated in vacuo and the resulting solid was recrystallized from water-MeOH (2:1, 6 mL) and dried in vacuum to afford (S)-3-((4-(4-fluoro-2-methylphenyl)piperazin-1-yl)methyl)-6a,7,8,9-tetrahydropyrido[3,2-e]pyrrolo[1,2-a]pyrazin-6(5H)-one (102.3 mg, 0.259 mmol, 56.7% yield) as an off-white solid. 1H NMR (400 MHz, DMSO-d6) δ ppm 1.80-2.02 (m, 3H) 2.09-2.20 (m, 1H) 2.23 (s, 3H) 2.37-2.49 (m, 4H) 2.77 (br. s., 4H) 3.34-3.44 (m, 3H) 3.52-3.65 (m, 1H) 3.93-4.03 (m, 1H) 6.88-7.07 (m, 4H) 7.62 (s, 1H) 10.44 (s, 1H). [M+H] calc'd for C22H26FN5O, 396. found, 396.
