Borane → 1-(4-Nitrobenzyl)piperidine

1-(4-Nitrobenzoyl)piperidine (0.1125 gms.) is then dissolved in tetrahydrofuran (1 mL) and slowly added dropwise to a 0° C., 1.0 M solution (4 mL) of Borane in tetrahydrofuran. The reaction mixture is maintained at 0° C. for 20 minutes following the completion of the addition to the Borane/tetrahydrofuran solution. The reaction mixture is then allowed to warm to room temperature, and is subsequently heated to 60° C. using an oil bath. The reaction mixture is maintained at 60° C. overnight, then is cooled to room temperature, and quenched with the addition of concentrated HCl (added until gas evolution stops). The quenched reaction mixture is then extracted with ethyl acetate and water. The organic layer is separated, and concentrated in vacuo, while the aqueous layer is separated and made basic with the addition of aqueous 1M NaOH. The basic aqueous layer is then extracted with ethyl acetate and the ethyl acetate layer from this extraction is concentrated in vacuo. The solids isolated from both concentrated ethyl acetate layers are combined to yield 92 mg of 1-(4-nitro-benzyl)-piperidine as a white-yellow solid.