Acetic Acid → tert-Butyl 4-hydroxy-[1,4'-bipiperidine]-1'-carboxylate

Participants

Reaction Steps

To 1-tert-butoxycarbonyl-4-piperidone (200 g, 1.01 mol) in tetrahydrofuran (THF) (1500 ml) was added 4-hydroxypiperidine (78.1 g, 0.77 mol). The resultant slurry was stirred for 30 minutes before cooling the reaction mixture with ice/water, acetic acid (47 ml) is then added (exotherm) which caused precipitation. The slurry was allowed to warm to room temperature before the addition of sodium triacetoxyborohydride (236 g, 1.12 mol) which was washed in with THF (500 ml). The resultant slurry was stirred overnight at room temperature. To the reaction mixture was added water (2000 ml) to give a solution. The solution was then extracted with diethyl ether (3×1800 ml). The aqueous phase was basified with 10% aq NaOH (950 ml) and extracted with dichloromethane (DCM) (3×1500 ml). The combined DCM layers are dried (MgSO4), filtered and the solvent removed to give the sub-titled compound as a yellow viscous oil, (177 g, 81%; MS: (M+H) 285).

Provenance & Evidence