Acetic Acid → 4-{1-[3-(Methyloxy)-4-nitrophenyl]-4-piperidinyl}-2-piperazinone

Participants

Reaction Steps

1-[3-(methyloxy)-4-nitrophenyl]-4-piperidinone (Example 57, step B) (1.00 g, 4.00 mmol) and 2-piperazinone (0.801 g, 8.00 mmol) were dissolved in 50 mL of toluene and 25 mL of acetonitrile with stirring. TEA (1.40 mL, 9.97 mmol) and HOAc (0.34 mL, 5.9 mmol) were added via syringe. Sodium triacetoxyborohydride (2.12 g, 10.0 mmol) was added in four equal portions over 1 h. The reaction was allowed to stir overnight and quenched by the addition of approximately 50 mL of 1N NaOH solution and 50 mL of MeOH. The mixture was stirred for 10 min and poured into H2O and EtOAc. The layers were separated, and the organic layer was washed with brine. The combined aqueous layers were extracted with DCM. The combined organic layers were dried over MgSO4, filtered, and concentrated in vacuo. The residue was purified by flash chromatography to afford 0.970 g (73%) of the title compound of step A. 1H NMR (400 MHz, DMSO-d6) δ 7.83 (d, J=9.5 Hz, 1H), 7.68 (br. s., 1H), 6.55 (dd, J=9.5, 2.4 Hz, 1H), 6.46 (d, J=2.56 Hz, 1H), 4.07-3.94 (m, 2H), 3.86 (s, 3H), 3.07 (br. s., 2H), 3.00 (s, 2H), 2.97-2.86 (m, 2H), 2.66-2.37 (m, 3H), 1.87-1.75 (m, 2H), 1.48-1.32 (m, 2H).

Provenance & Evidence