Ethyl 4-oxo-1-piperidinecarboxylate → HCID 24883127, compound

Participants

Reaction Steps

(3aS,7aS)-1-isopropyl-3-piperidin-4-yloctahydro-2H-benzimidazol-2-one (85 mg, 0.3 mmol) was dissolved in MeOH (2 mL) and ethyl 4-oxopiperidine-1-carboxylate (48 μL, 0.32 mmol) was added. A solution of sodium cyanoborohydride (31 mg, 0.45 mmol) and zinc chloride (20 mg, 0.15 mmol) in MeOH (1 mL) was then added drop wise at room temperature. The mixture was then stirred for 3 hours and then more sodium cyanoborohydride (40 mg) was added and the mixture stirred at room temperature over night. The solvent was then removed under reduced pressure and the residue was diluted in dichloromethane (80 mL) and was washed with 1N NaOH (5 mL), brine and then dried and concentrated in vacuo. The residue was purified by high pH prep LCMS to provide the title compound (30 mg). Free Base-1H NMR (400 MHz, METHANOL-D4): δ ppm 1.14 (dd, J=6.84, 5.27 Hz, 6H), 1.20 (t, J=7.23 Hz, 3H), 1.28-1.45 (m, 6H), 1.54 (d, J=12.50 Hz, 1H), 1.61-1.69 (m, 1H), 1.75-1.92 (m, 6H), 2.12-2.32 (m, 4H), 2.38-2.52 (m, 1H), 2.64-2.81 (m, 2H), 2.80-2.92 (m, 2H), 2.92-3.05 (m, 2H), 3.52-3.65 (m, 1H), 3.83-3.98 (m, 1H), 4.05 (q, J=7.03 Hz, 2H), 4.13 (d, J=13.28 Hz, 2H). MS (M+1): 421.4

Provenance & Evidence