Reacción #65536

Ecuación de reacción

sodium hydroxide

4-methylthiosemicarbazide

phosphorus oxychloride

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

→

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

Rendimiento 81.3%

Disolventes

water

tetrahydrofuran

tetrahydrofuran

tetrahydrofuran

dimethylformamide

Condiciones de reacción

Tratamiento posterior

1. 1
   Otroat -5°
2. 2
   Otro∫5° C.
3. 3
   workup.STIRRINGby stirring at the same temperature for 30 minutes
4. 4
   workup.STIRRINGwith stirring
5. 5
   workup.STIRRINGThe mixture was stirred at the same condition for 2 hours
6. 6
   OtroTetrahydrofuran was evaporated under reduced pressure
7. 7
   Otroto give
8. 8
   Otroprecipitates
9. 9
   FiltraciónThe precipitates were collected by filtration
10. 10
    Lavadowashed with water and diisopropyl ether successively
11. 11
    Secadodried over phosphorus pentoxide

Procedimiento

To a mixture of dimethylformamide (2.9 ml) and tetrahydrofuran (6 ml) was dropwise added phosphorus oxychloride (2.8 ml) at -5°∫5° C. and the mixture was stirred at the same temperature for 30 minutes. To the mixture was added a solution of (2S,4R)-2- carboxy-4-methanesulfonyloxy-1-(4-nitrobenzyloxycarbonyl)pyrrolidine (9.65 g) in tetrahydrofuran (20 ml) at -5°∫5° C., followed by stirring at the same temperature for 30 minutes. The mixture was dropwise added to a solution of 4-methylthiosemicarbazide (25 g) in a mixture of water (200 ml) and tetrahydrofuran (200 ml) at 0°-10° C. with stirring, keeping the pH between 8-9 with 1N aqueous sodium hydroxide. The mixture was stirred at the same condition for 2 hours. Tetrahydrofuran was evaporated under reduced pressure to give precipitates. The precipitates were collected by filtration, washed with water and diisopropyl ether successively, and dried over phosphorus pentoxide to give (2S, 4R)-4-methanesulfonyloxy -2-(4-methylthiosemicarbazidocarbonyl)-1-(4-nitrobenzyloxycarbonyl) pyrrolidine (9.61 g).

Fuente