Trifluoroacetic acid → Ammonia

Participants

Reaction Steps

1-Benzyl-4-hydroxypiperidine (1.5 g, 7.8 mmol) and 3-hydroxy-2-methylpyridine (1.75 g, 16 mmol) were added to mixture of polymer supported triphenylphosphine (1 g, 3 mmol) and di-tert-butyl azodicarboxylate (3.61 g, 16 mmol) in dichloromethane (10 mL) and the mixture was stirred at room temperature for 3 hours. Trifluoroacetic acid (16 mL) was then added and the mixture was stirred for a further hour then concentrated in vacuo. The residue was suspended in dichloromethane and basified with 2M sodium hydroxide solution (5 mL). The organic layer was separated, washed with brine, dried over magnesium sulfate and concentrated in vacuo. Purification of the residue by column chromatography on silica gel, eluting with dichloromethane:methanol:0.88 ammonia, 90:10:1, to afford the title compound as a liquid in 51% yield, 1.12 g. 1H NMR(CDCl3, 400 MHz) δ: 1.79-1.88(m, 2H), 1.90-2.01(m, 2H), 2.25-2.41(m, 2H), 2.44(s, 3H), 2.64-2.78(m, 2H), 3.53(s, 2H), 4.28-4.39(m, 1H), 7.00-7.09(m, 2H), 7.19-7.38(m, 5H), 8.14(m, 1H); LRMS APCI m/z 283 [M+H]+

Provenance & Evidence