Dimethyl Sulfoxide → Tert-butyl 4-(3-oxopropyl)piperidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of oxalyl chloride (2 mL, 22 mmol) in dry dichloromethane (50 mL) at −78° C. under argon, was added dropwise a solution of dimethylsulfoxide (3.4 mL, 44 mmol) in dichloromethane (10 mL). After 2 min, a solution of 3-[N-(t-butoxycarbonyl)piperidin-4-yl]propanol (4.86 g, 20 mmol) in dichloromethane (10 mL) was added dropwise over 5 min. After stirring an additional 15 min at −78° C., triethylamine (14 mL) was added dropwise. After 5 min, the reaction became a thick white slurry and was allowed to warm to RT and stirred for 16 h. The reaction mixture was washed with cold 1N hydrochloric acid and with brine, dried (magnesium sulfate) and concentrated. The residue was purified by flash chromatography (silica gel, 30% ethyl acetate/hexane) to yield the title compound (4.18 g, 87%). TLC Rf 0.40 (30% ethyl acetate/hexane); 1H NMR (CDCl3) δ0.95-1.80 (7H, m), 1.48 (9H, s), 2.40-2.90 (4H, m), 4.14 (2H, br dt), 9.88 (1H, t).

Provenance & Evidence