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

Participants

Reaction Steps

A solution of 1-tert-butoxycarbonyl isonipecotic acid (40 g, 0.17 mol) and N-methylmorpholine (19 mL, 0.17 mol) in tetrahydrofuran (900 mL) at −10° C. was treated with ethyl chloroformate (17 mL, 0.17 mol). After 0.5 h, sodium borohydride was added (19.8 g, 0.5 mol) in one portion followed by slow addition of methanol. After gas evolution ceased, the mixture was concentrated and the residue was diluted with 10% aqueous acetic acid and partitioned between ethyl acetate and water. The aqueous layer was washed with EtOAc (2×) and the combined organic extracts were dried with magnesium sulfate, filtered, and concentrated to a solid residue which was purified by column chromatography (SiO2: 10 to 50% EtOAc:hexanes) providing the title compound (33.8 g, 90%) as a white solid.

Provenance & Evidence