Reaktion #1182698

Reaktionsgleichung

ethyl acetate hexane

isatin

ethyl potassium malonate

→

Indole

Lösungsmittel

ethanol pyridine acetic acid

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwas added
2. 2
   Temperaturthe mixture was heated
3. 3
   Temperaturunder reflux in accordance with the times
4. 4
   workup.DISTILLATIONthe solvent mixture was distilled off in vacuo
5. 5
   Extraktionthe mixture was extracted
6. 6
   SonstigeAfter separation of the phases
7. 7
   Extraktionthe aqueous phase was extracted twice with ethyl acetate (30 ml each time)
8. 8
   WaschenThe combined organic phases were washed with 2N HCl (50 ml)
9. 9
   Trocknendried over Na2SO4
10. 10
    Einengenconcentrated to 20 ml in vacuo
11. 11
    workup.ADDITIONHexane was added to the solution until crystallization of the corresponding 3-hydroxy-2-oxo-2,3-dihydro-1H-indol-3-yl)acetic acid ethyl ester (2a-2d)
12. 12
    Sonstigethe crystallization to completion
13. 13
    FiltrationThe solid was filtered off with suction
14. 14
    Sonstigedried in vacuo

Vorschrift

The corresponding isatin 1a-1d (10 mmol) was dissolved in a mixture of ethanol/pyridine/acetic acid (50 ml, 15:5:2), ethyl potassium malonate (1.87 g, 11 mmol) was added and the mixture was heated under reflux in accordance with the times stated in the table. The course of the reaction was monitored by means of TLC (eluent: ethyl acetate/hexane 1:1). For working up, the solvent mixture was distilled off in vacuo. The residue was taken up in ethyl acetate (50 ml) and the mixture was extracted by shaking with water (50 ml). After separation of the phases, the aqueous phase was extracted twice with ethyl acetate (30 ml each time). The combined organic phases were washed with 2N HCl (50 ml), dried over Na2SO4 and concentrated to 20 ml in vacuo. Hexane was added to the solution until crystallization of the corresponding 3-hydroxy-2-oxo-2,3-dihydro-1H-indol-3-yl)acetic acid ethyl ester (2a-2d) started. To bring the crystallization to completion, the mixture was cooled to 10° C. for 12 h. The solid was filtered off with suction and dried in vacuo.

Quelle