Ethyl nipecotate → Ethyl (S)-3-Piperidinecarboxylate D-Tartrate

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Reaction Steps

Ethyl nipecotate (70.2 g, 0.446 mmol) and D-tartaric acid (67.0 g, 1.0 eq.) were dissolved in hot 95% EtOH (350 mL). The resulting solution was cooled to room temperature, filtered, and the crystals washed with ice-cold 95% EtOH. The product was then recrystallized from 95% EtOH (550 mL) to give ethyl (S)-nipecotate D-tartrate (38.5 g, 56% yield). The salt (38.5 g) was dissolved in water (300 mL), cooled to 0° C., and 3M NaOH was added until the pH was 9-10. The resulting solution was extracted with CH2Cl2 (5×100 mL) and the combined organics dried over Na2SO4, filtered, and concentrated under reduced pressure to give Compound (41) as a clear oil (19 g, 89% yield). CIMS: MH+=158.

Provenance & Evidence