反応 #51636

反応方程式

acetic anhydride

estradiol

acetone CH2Cl2

→

diacetate

収率 95.0%

Estradiol Diacetate

収率 95.0%

溶媒

pyridine

反応条件

後処理

1. 1
   その他a complete reaction
2. 2
   温度The mixture was cooled in an ice bath
3. 3
   その他the 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
   温度to warm to room temperature
6. 6
   その他The solvents were removed in vacuo
7. 7
   その他the solid residue crystallized from hot methanol

実験手順

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%).

出典