Tert-Butyl 4-{4-Chloro-2-[(1S)-1-(Azido)Ethyl]Phenyl}-3,6-Dihydropyridine-1-Carboxylate → Tert-Butyl 4-{2-[(1S)-1-Aminoethyl]-4-Chlorophenyl]Piperidine-1-Carboxylate

Participants

Reaction Steps

A mixture of tert-butyl 4-{4-chloro-2-[(1S)-1-(azido)ethyl]phenyl}-3,6-dihydropyridine-1-carboxylate (3-6) (22.9 g, 63.1 mmol) and platinum (IV) oxide (1.08 g, 4.73 mmol) in ethanol/glacial acetic acid (1:1, 200 mL) was hydrogenated at atmospheric pressure for approximately 15 h. The resulting mixture was degassed via three vacuum/hydrogen ingress cycles to remove the liberated nitrogen and the hydrogenation was then continued for a further 24 h. The reaction mixture was filtered through a short column of celite®, eluted copiously with ethanol. The filtrate was evaporated and the residue was partitioned between methylene chloride and 1N sodium hydroxide. The organic layer was separated and the aqueous phase was re-extracted twice with methylene chloride. The combined organic extracts were washed with water, brine, dried (Na2SO4), and concentrated in vacuo to give crude (˜70% pure) 3-7 as a colorless foam.

Provenance & Evidence