Imidazole → Tert-butyl 4-(2-iodoethyl)piperidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

Combined 4-(2-hydroxyeth-1-yl)-1-tert-butoxylcarbonylpiperidine (37.4 g, 0.16 mol, from Step B), triphenylphosphine (55 g, 0.21 mol) and imidazole (14 g, 0.21 mol) in 800 mL of 33% acetonitrile in ether. Cooled to 0° C. and added iodine (56 g, 0.22 mol) portionwise. The iodine is de-colored until the endpoint of the reaction. Diluted with 1 L of ether. Washed organic layer with 2×500 mL each of sat'd. aq. Na2S2O3, sat. aq. CuSO4 and brine. Dried over magnesium sulfate, filtered and concentrated. Triphenylphosphine oxide precipitates. Added ether and filtered the slurry through a plug of silica gel. Purified a portion of the crude material by flash chromatography (5% ethyl acetate in hexane eluent) to afford the title compound.

Provenance & Evidence