Dimethyl Sulfoxide → benzyl (2S,3S)-3-hydroxy-2-methylpyrrolidine-1-carboxylate

To a suspension of (4S,5S)-4-hydroxy-5-methylpyrrolidin-2-one (10.45 g) in dry THF (418 mL) was added dropwise Red-Al (104.9 g: 363 mmol: 70% toluene solution) under ice-cooling and a nitrogen stream. The mixture was stirred at room temperature for 20 min, and further refluxed for 3 hr. The reaction mixture was ice-cooled again, and sodium carbonate decahydrate (41.6 g) was added under a nitrogen stream. The mixture was stirred at room temperature overnight, insoluble materials were filtered through celite and washed with THF. The filtrate and washing were combined and concentrated under reduced pressure to give (2S,3S)-3-hydroxy-2-methylpyrrolidine. Without further purification, this compound was diluted with DMSO to give 0.9 mol/L-DMSO solution. A solution (170 mL) of (2S,3S)-3-hydroxy-2-methylpyrrolidine in 0.9 mol/L-DMSO was diluted with water (200 mL), sodium hydrogen carbonate (24.6 g) and benzyl chloroformate (15 mL) were added, and the mixture was stirred at room temperature for 18 hr. Water was added to the reaction mixture, and the mixture was extracted with ethyl acetate. The extract was washed with saturated brine, dried over anhydrous sodium sulfate, and concentrated under reduced pressure to give the title compound as a pale-yellow oil (yield: 20.64 g, 84%).

1. customWithout further purification
2. additionthis compound was diluted with DMSO
3. customto give 0.9 mol/L-DMSO solution
4. additionwere added
5. extractionthe mixture was extracted with ethyl acetate
6. washThe extract was washed with saturated brine
7. dry with materialdried over anhydrous sodium sulfate
8. concentrationconcentrated under reduced pressure

ORDレコード

ord-0176cd0c43b54ef6a15be64fe86a6ae5

出典データセット

uspto-grants-2013_04

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US08420694B2