(3R,4R)-1-tert-butyl 3-ethyl 4-((R)-1-phenylethylamino)-piperidine-1,3-dicarboxylate → (3R,4R)-1-tert-butyl 3-ethyl 4-aminopiperidine-1,3-dicarboxylate

Participants

Reaction Steps

In a dry 500-mL Paar flask charged with Palladium hydroxide (20 wt % Pd, dry basis, on carbon, 1.50 g) was added ethanol (75 mL) and (3R,4R)-4-[(R)-1-phenyl-ethylamino]-piperidine-1,3-dicarboxylic acid 1-tert-butyl ester 3-ethyl ester (4.30 g, 11.4 mmol). The reaction mixture was hydrogenated at 53 psi for 20.5 hours with vigorous shaking. The reaction mixture was filtered through a plug of celite. The plug was washed with 20 mL of ethanol and the combined filtrates were concentrated in vacuo to give a colorless oil (3.07 g, 99%). 1H NMR (300 MHz, CDCl3), δ: 4.32 (bs, 1H), 4.19 (q, 2H, J=7), 4.19 (bs, 1H), 3.08 (td, 1H, J=11, J′=3), 2.75 (bt, 2H, J=14), 2.29 (td, 1H, J=11, J′=4), 1.89 (m, 1H), 1.46 (s, 9H), 1.38 (td, 1H, J=12, J′=5), 1.28 (t, 3H, J=7).

Provenance & Evidence