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

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).

1. customcondensed under reduced pressure
2. customto give a solid
3. temperatureThe solution was heated to 60° C. for 3 hours
4. customcondensed under reduced pressure
5. customthe resultant oil purified via silica gel chromatography (50-80% acetate/hexanes followed by 12% methanol/dichloromethane)

ORD record

ord-0b42fcbaf913478e90fb962e061db49b

Source dataset

uspto-grants-2012_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08101588B2