Triethylamine → 3-Pyrrolidinone benzyl carbamate

Participants

Reaction Conditions

Reaction Steps

To a solution of 31.6 g (0.14 mmol) of 3-pyrrolidinol benzyl carbamate, from Step 1, in 275 mL of DMSO cooled to 0° C. was added 159.25 mL (1.12 mmol) of triethylamine. To this solution, maintained at 0° C. with stirring, was added dropwise over a one hour period a solution of 68.18 g (0.42 mmol) of sulfur trioxide pyridine complex in 250 mL of DMSO. The solution was stirred an additional half-hour at 0° C., then the ice bath was removed and the reaction allowed to proceed for 20 hours at room temperature. The DMSO solution was then poured into 1 L of 20% sodium chloride solution and the product was extracted with three washings of methylene chloride. The methylene chloride solution was washed with 20% NaCl solution to remove excess DMSO, dried over anhydrous sodium sulfate, filtered, and the solvent was removed by evaporation. The dark liquid residue was distilled in a kugelrohr apparatus (140°-160° C. @ 5 Torr) and further purified by chromatography on silica gel (solvent 0.5-2.0% methanol in chloroform) to afford the title compound, MS M/Z 220 (M+H); NMR: d 2.61 (t,2H, J=7.5 Hz), 3.82 (s, 2H), 3.85 (t, 2H, J=7.5 Hz), 5.18 (s, 2H), 7.37 (m, 5H).

Provenance & Evidence