tert-Butyl 4-(3-aminophenyl)-5,6-dihydropyridine-1(2H)-carboxylate → tert-Butyl 4-(3-aminophenyl)piperidine-1-carboxylate

Participants

Reaction Steps

A mixture of 3.10 g of tert-butyl 4-(3-aminophenyl)-1,2,3,6-tetrahydropyridine-1-carboxylate (11.3 mmol) and 1.0 g of 10% Pd/C in 200 mL of ethanol was hydrogenated at room temperature using the balloon method for 2 days. The reaction mixture was filtered and washed with ethanol. The combined ethanol extracts were concentrated in vacuo and the residue was chromatographed on silica (dichloromethane:methanol 95:5 with 1% isopropylamine added to protect the BOC group from hydrolysis) to give 2.63 g of the desired product (84%). 1H NMR (400 MHz, CDCl3) δ 7.10 (t, 1H, J=7.60 Hz), 6.62 (d, 1H, J=8.4 Hz), 6.60–6.59 (m, 2H), 4.27–4.18 (m, 2H), 3.62–3.58 (m, 2H), 2.80–2.72 (m, 2H), 2.62–2.59 (m, 1H), 1.89–1.52 (m, 4H) 1.49 (s, 9H); ESMS m/e: 277.2 (M+H)+.

Provenance & Evidence