Tributylstannane → 4-Benzoyloxy-1-methoxy-2,2,6,6-tetramethylpiperidine

Participants

Reaction Steps

The reaction is carried out in a nitrogen atmosphere. Tributyltin hydride (20.0 grams, 68.7 mmol) is added dropwise over 2.75 hours to a solution, precooled to 10° C., of 40.0 grams (145 mmol) of 4-benzoyloxy-1-oxyl-2,2,6,6-tetramethylpiperidine, 9.0 grams (33.6 mmol) of methylene iodide (diiodomethane) and 75 ml of chlorobenzene. The reaction temperature reaches 27° C. during the addition. The red mixture is stirred at room temperature for 27 hours after the addition is complete. The reaction mixture is then passed through a column of silica gel (heptane, then 100:3 heptane:ethyl acetate). Fractions containing the desired product are concentrated to give a crude solid. Tributyltin iodide is removed by washing a solution of the crude solid with aqueous ammonia. Final purification by flash chromatography on silica gel (100:3 heptane:ethyl acetate) followed by recrystallization from heptane affords 4.8 grams of the title compound as a white solid melting at 126°-127° C.

Provenance & Evidence