Triethylamine → (S)-(-)-4-azido-2-pyrrolidinone

Participants

Reaction Steps

To an ice cooled solution of (R)-(+)-4-hydroxy-2-pyrrolidinone (25.0 g., 247 mmol) in dichloromethane (300 mL) was added triethylamine (17.0 g., 168.7 mmol) and methane sulfonyl chloride (21 mL, 272 mmol) dropwise. The solution was stirred at ambient temperature for one hour. The reaction was monitored via TLC (100% ethyl acetate using permanganate stain). The solution was then condensed under reduced pressure to give a solid. The solid was diluted with DMF (300 mL) followed by the addition of sodium azide (48.24 g., 742 mmol). The solution was heated to 60° C. for 3 hours. The reaction was monitored via TLC (100% ethyl acetate using permanganate stain). The solution was then condensed under reduced pressure and the resultant oil purified via silica gel chromatography (50-80% acetate/hexanes followed by 12% methanol/dichloromethane) to afford the title compound (10.2 g., 32%). 1H-NMR (CD3OD) δ 4.43 (m, 1H), 3.71 (dd, 1H), 3.34 (m, 1H), 2.75 (dd, 1H), 2.29 (dd, 1H).

Provenance & Evidence