Reaktion #74474

Reaktionsgleichung

5-(2-chloro-5-((2S,3S,4R,5R,6R)-3,4,5-tris(benzyloxy)-6-(benzyloxymethyl)-tetrahydro-2H-pyran-2-yl)benzyl)-1,3,4-thiadiazol-2-amine

5-(2-Chloro-5-((2S,3S,4R,5R,6R)-3,4,5-tris(benzyloxy)-6-(benzyloxymethyl)-tetrahydro-2H-pyran-2-yl)benzyl)-1,3,4-thiadiazol-2-amine

hydrochloric acid

sodium nitrite

→

title compound

Ausbeute 22.0%

2-Chloro-5-(2-chloro-5-((2S,3S,4R,5R,6R)-3,4,5-tris(benzyloxy)-6-(benzyloxymethyl)-tetrahydro-2H-pyran-2-yl)benzyl)-1,3,4-thiadiazole

Ausbeute 22.0%

Lösungsmittel

acetic acid

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturwhile maintaining an internal reaction temperature below 10° C
2. 2
   workup.STIRRINGthe resulting mixture was stirred
3. 3
   Temperaturwith gradual warming to ambient temperature over 2 h
4. 4
   Extraktionextracted with ethyl acetate
5. 5
   TrocknenThe organic layer was dried over magnesium sulfate
6. 6
   Filtrationfiltered
7. 7
   Sonstigeevaporated in vacuo
8. 8
   SonstigeFlash chromatography on a Biotage® purification apparatus (silica gel, 10 to 60% ethyl acetate in hexanes)

Vorschrift

To a mixture of 5-(2-chloro-5-((2S,3S,4R,5R,6R)-3,4,5-tris(benzyloxy)-6-(benzyloxymethyl)-tetrahydro-2H-pyran-2-yl)benzyl)-1,3,4-thiadiazol-2-amine (4.0 mmol) from Step 1 and copper (0.04 g, 0.62 mmol) in hydrochloric acid (37%, 6 mL) and acetic acid (30 mL) at 0° C. was slowly added sodium nitrite (2.8 g, 40 mmol) while maintaining an internal reaction temperature below 10° C. After 1 h stirring at 0° C., the resulting mixture was stirred with gradual warming to ambient temperature over 2 h. The mixture was diluted with water and extracted with ethyl acetate. The organic layer was dried over magnesium sulfate, filtered and evaporated in vacuo. Flash chromatography on a Biotage® purification apparatus (silica gel, 10 to 60% ethyl acetate in hexanes) yielded the title compound (0.66 g, 0.86 mmol, 22%) as yellow oil.

Quelle