Hydrochloric Acid → 3-(2-Ethoxyphenoxy)piperidine hydrochloride

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Aqueous 12.2M hydrochloric acid solution (80.0 mL, 0.976 mol) was added slowly to a mixture of 3-(2-ethoxyphenoxy)pyridine (210 g, 0.976 mol), rhodium (5% on alumina, 21 g, 0.010 mol), and methanol (2.1 L) in a Parr reactor. The reactor was purged sequentially with nitrogen and hydrogen (4 times each), and then was heated to 50° C. and pressurized to 50 psi with hydrogen. After 9 hours, the reactor was cooled to 25° C. and was purged with nitrogen. The catalyst was removed by filtration, rinsing with methanol. The resulting methanol solution was distilled to a low volume under reduced pressure at 50-55° C.; ethyl acetate (2.3 L) was added and the distillation was continued at ambient pressure and at constant volume with the addition of further ethyl acetate (1.5 L). The distillation was stopped when the solution became turbid. The mixture was cooled to 20° C. and the resulting crystals were collected by filtration, rinsing with ethyl acetate (0.70 L), to afford after drying 3-(2-ethoxyphenoxy)piperidine hydrochloride (201 g). 1H NMR (400 MHz, DMSO-d6) δ 9.20 (br s, 2H), 7.12 (d, 1H), 7.03 (m, 2H), 6.89 (m, 1H), 4.45 (m, 1H), 4.04 (q, 2H), 3.27 (app dd, 1H), 3.05 (m, 3H), 1.94 (m, 2H), 1.72 (m, 2H), 1.35 (t, 3H). MS (ES+) 222.1 (M+H).

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