Reaktion #65553

Reaktionsgleichung

(2S, 4R)-4-methanesulfonyloxy-1-(4-nitrobenzyloxycarbonyl) -2-thiocarbamoylpyrrolidine

ethyl bromopyruvate

→

(2S,4R)-2- (4-carboxythiazol-2-yl)-4-methanesulfonyloxy-1-(4-nitrobenzyloxycarbonyl) pyrrolidine

Lösungsmittel

dichloromethane

ethanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigethe mixture was evaporated
2. 2
   workup.DISSOLUTIONThe residue was dissolved in ethyl acetate
3. 3
   Waschenwashed with saturated sodium bicarbonate and brine successively
4. 4
   SonstigeThe dried organic layer was evaporated
5. 5
   workup.DISSOLUTIONthe residue was dissolved in tetrahydrofuran (15 ml) and in sodium hydroxide (15 ml)
6. 6
   workup.STIRRINGAfter stirring at 35°-45° C. for 1 hour
7. 7
   Sonstigethe mixture was evaporated
8. 8
   workup.ADDITIONpoured into ethyl acetate
9. 9
   workup.ADDITIONTo this mixture was added 1N hydrochloric acid (20 ml)
10. 10
    Sonstigeorganic layer was separated
11. 11
    Waschenwashed with brine
12. 12
    SonstigeThe dried organic layer was evaporated

Vorschrift

To a solution of (2S, 4R)-4-methanesulfonyloxy-1-(4-nitrobenzyloxycarbonyl) -2-thiocarbamoylpyrrolidine (2.0 g) in dichloromethane (40 ml) was added a solution of ethyl bromopyruvate (1.04 ml) in absolute ethanol (10 ml) at 0° C. After stirring at room temperature for 2 hours, the mixture was evaporated. The residue was dissolved in ethyl acetate, and washed with saturated sodium bicarbonate and brine successively. The dried organic layer was evaporated and the residue was dissolved in tetrahydrofuran (15 ml) and in sodium hydroxide (15 ml). After stirring at 35°-45° C. for 1 hour, the mixture was evaporated and poured into ethyl acetate. To this mixture was added 1N hydrochloric acid (20 ml), and then organic layer was separated, and washed with brine. The dried organic layer was evaporated to give (2S,4R)-2- (4-carboxythiazol-2-yl)-4-methanesulfonyloxy-1-(4-nitrobenzyloxycarbonyl) pyrrolidine (1.54 g).

Quelle