Reaktion #1177035

Reaktionsgleichung

ethyl acetate hexane

2-[2-(1-Methylfluoren-9-yl)ethyl]-1,3-dioxolane

→

3-(1-methylfluoren-9-yl)propionic acid

Ausbeute 59.9%

Lösungsmittel

acetone

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigethe acetone was evaporated
2. 2
   Extraktionthe residual water was extracted with ethyl acetate twice
3. 3
   WaschenThe combined organic layers were washed with water until water
4. 4
   ExtraktionThe organic solution was then extracted with 1N aqueous solution of sodium hydroxide
5. 5
   WaschenThe basic aqueous solution was washed with ethyl acetate
6. 6
   Extraktionextracted with ethyl acetate again
7. 7
   TrocknenThe ethyl acetate solution was dried over magnesium sulfate
8. 8
   Sonstigeevaporated
9. 9
   SonstigePurification of the crude by short path chromatography (silica, 25% ethyl acetate/hexane)

Vorschrift

2-[2-(1-Methylfluoren-9-yl)ethyl]-1,3-dioxolane (4.8 g, 17.2 mmol) in 100 mL of acetone was charged slowly with John's reagent (CrO3 : H2SO4 :H2O 4:4:50 by weight) at room temperature. The reaction was monitored by TLC (silica, 10% ethyl acetate/hexane). The reaction mixture was stirred for 6 hr at room temperature, the acetone was evaporated and the residual water was extracted with ethyl acetate twice. The combined organic layers were washed with water until water became colorless. The organic solution was then extracted with 1N aqueous solution of sodium hydroxide. The basic aqueous solution was washed with ethyl acetate, acidified and extracted with ethyl acetate again. The ethyl acetate solution was dried over magnesium sulfate and evaporated. Purification of the crude by short path chromatography (silica, 25% ethyl acetate/hexane) afforded 2.6 g (59.9%) of 3-(1-methylfluoren-9-yl)propionic acid.

Quelle