Reaktion #155664

Reaktionsgleichung

acetic anhydride

Endothall

→

product

Ausbeute 50.6%

Endothall Anhydride

Ausbeute 50.6%

Lösungsmittel

benzene

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigehad gone into solution (2 hours)
2. 2
   TemperaturThe solution was heated under vacuum
3. 3
   Sonstigeto remove the benzene
4. 4
   workup.ADDITIONPetroleum ether (5 mL) was then added
5. 5
   Sonstigethe desired anhydride spontaneously crystallized
6. 6
   SonstigeThe product was removed by filtration
7. 7
   Waschenwashed with a little petroleum ether

Vorschrift

As shown in scheme 1, we prepared endothal anhydride by adding acetic anhydride (0.5 mL) (4) to a suspension of Endothall (186 mg) (3) in benzene (3 mL) and the mixture was then stirred until the solid had gone into solution (2 hours). The solution was heated under vacuum to remove the benzene and the residue was then heated at 80° C. for 30 min. Petroleum ether (5 mL) was then added and the desired anhydride spontaneously crystallized. The product was removed by filtration washed with a little petroleum ether to give the pure product (85 mg) which was used immediately in the following two preparations.

Quelle