Reaktion #51636

Reaktionsgleichung

acetic anhydride

estradiol

acetone CH2Cl2

→

diacetate

Ausbeute 95.0%

Estradiol Diacetate

Ausbeute 95.0%

Lösungsmittel

pyridine

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigea complete reaction
2. 2
   TemperaturThe mixture was cooled in an ice bath
3. 3
   Sonstigethe excess acetic anhydride quenched by addition of methanol (25 mL)
4. 4
   workup.STIRRINGThe mixture was stirred at 0° C. for one hour
5. 5
   Temperaturto warm to room temperature
6. 6
   SonstigeThe solvents were removed in vacuo
7. 7
   Sonstigethe solid residue crystallized from hot methanol

Vorschrift

Under nitrogen, acetic anhydride (50 mL, 264.5 mmol) was added to a solution of estradiol (1a) (20.0 g, 73.43 mmol) in dry pyridine (200 mL). The reaction mixture was stirred at room temperature overnight (16 h). The next morning, analysis by tlc (5% acetone/CH2Cl2) indicated a complete reaction. The mixture was cooled in an ice bath and the excess acetic anhydride quenched by addition of methanol (25 mL). The mixture was stirred at 0° C. for one hour and then allowed to warm to room temperature. The solvents were removed in vacuo and the solid residue crystallized from hot methanol to give the pure diacetate (2a) (24.87 g, 95%).

Quelle