Ammonium Acetate → tert-Butyl 4-(1-aminoethyl)piperidine-1-carboxylate

Participants

Reaction Steps

A mixture of tert-butyl 4-acetylpiperidine-1-carboxylate (145 g, 0.64 mol) and ammonium acetate (225 g, 2.9 mol) in methanol (2 L) was stirred at room temperature for 1.5 hours. Sodium cyanoborohydride (30 g, 0.48 mol) was added in one portion and the stirring was continued overnight at room temperature. The reaction mixture was poured in 2N aq. NaOH (2 L) and extracted with dichloromethane (2×1 L). The combined extracts were washed with water (1 L), brine (0.3 L), and evaporated to dryness. The residue was dissolved in TBME (1.5 L), dried over sodium sulfate, filtered, and evaporated to dryness under reduced pressure. The residue was purified by bulb to bulb distillation at 180° C. and 0.1 mbar to afford the title compound as a colorless oil that partly solidified upon standing (131 g, 90% yield).

Provenance & Evidence