4-Methylmorpholine → Tert-butyl 4-(hydroxymethyl)piperidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of Boc-isonipecotic acid (40 g, 0.17 mol) and N-methylmorpholine (19 mL, 0.17 mol) in tetrahydrofuran (900 mL) stirring at −10° C., ethyl chloroformate was slowly added (17 mL, 0.17 mol) via addition funnel. After 30 min, sodium borohydride was added (19.8 g, 0.5 mol) in one portion. The reaction mixture was stirred at −10° C. for 1 h; then it was slowly quenched with methanol. The solvent was removed in vacuo; the resulting residue was diluted with 10% aqueous acetic acid and partitioned between ethyl acetate and water. The aqueous layer was separated and extracted with additional ethyl acetate (2×500 mL). The combined organic extracts were dried with magnesium sulfate, filtered, and concentrated in vacuo to a solid residue which was chromatographed on silica gel. Elution with ethyl acetate-hexanes (1:9 to 1:1) provided the title compound (33.8 g, 90%) as a white solid.

Provenance & Evidence