Sodium Azide → ethyl (S)-4-azido-3-hydroxybutyrate

To a mixture of ethyl (S)-4-chloro-3-hydroxybutyrate (1 93 g, 1.16 mol, optical purity:98.5% ee) and N,N-dimethylformamide (1.4 Lit.) is added sodium azide (151 g, 2.32 mol) and the mixture was stirred at 100°-110° C. for 2 hours. After cooling N,N-dimethylformamide was distilled off and to the residue was added water (1 Lit.). The mixture was extracted with ethyl acetate and the extract was dried over magnesium sulfate. By distillation off ethyl acetate under vacuo, there is obtained ethyl (S)-4-azido-3-hydroxybutyrate as a crude product (206 g). Then the crude product was dissolved in methanol (1 Lit.) and to it 5% palladium-carbon (10 g) was added. The mixture was stirred for 17 hours at room temperature under a hydrogen atmosphere. After the reaction was over, palladium-carbon was filtered off and the solvent was distilled off under vacuo. The resulting product was recrystallized from acetone-water to give (S)-4-hydroxy-2-pyrrolidone (99 g, 0.98 mol, yield:84%) as a colorless crystalline solid. Optical purity:98.3% ee, Specific rotation:[α]D22 -57.6°(c=1.00, H2O).

1. distillationwas distilled off and to the residue
2. additionwas added water (1 Lit.)
3. extractionThe mixture was extracted with ethyl acetate
4. dry with materialthe extract was dried over magnesium sulfate
5. distillationBy distillation off ethyl acetate under vacuo

ORD-Eintrag

ord-71e6b906275546c6a3582fbc70047819

Quelldatensatz

uspto-grants-1999_02

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05869694