Diisopropylethylamine → (S)-3-((4-(4-chlorophenyl)piperazin-1-yl)methyl)-6a,7,8,9-tetrahydropyrido[3,2-e]pyrrolo[1,2-a]pyrazin-6(5H)-one

Participants

Reaction Conditions

Reaction Steps

(S)-3-(hydroxymethyl)-6a,7,8,9-tetrahydropyrido[3,2-e]pyrrolo[1,2-a]pyrazin-6(5H)-one (200 mg, 0.912 mmol), 1-(4-chlorophenyl)piperazine hydrochloride (200 mg, 0.858 mmol), N,N-diisopropylethylamine (DIPEA; 0.50 mL), and (cyanomethyl)trimethylphosphonium iodide (220 mg, 1.08 mmol) were suspended in propionitrile (2 mL) and heated in a closed vial at 90° C. for 4 h. The reaction mixture was diluted with MeOH (2 mL) and purified using preparative scale HPLC (45-95% acetonitrile in water, buffered with NH4HCO3). The fractions containing product were concentrated in vacuo and diluted with water (5 mL). The resulting precipitate was filtered and dried in vacuum to afford the title compound as an off-white solid (135 mg, 40%). 1H NMR (DMSO-d6) δ (ppm): 10.43 (s, 1H), 7.61 (d, J=1.8 Hz, 1H), 7.21 (d, J=8.8 Hz, 2H), 6.98 (d, J=1.8 Hz, 1H), 6.92 (d, J=9.1 Hz, 2H), 3.91-4.06 (m, 1H), 3.51-3.66 (m, 1H), 3.37-3.47 (m, 1H), 3.10 (br. s., 4H), 2.46 (d, J=4.3 Hz, 4H), 2.09-2.26 (m, 1H), 1.80-2.03 (m, 3H); [M+H] calc'd for C21H24ClN3O, 398; found, 398; melting point 265-268° C.

Provenance & Evidence