Reacción #1182698

Ecuación de reacción

ethyl acetate hexane

isatin

ethyl potassium malonate

→

Indole

Disolventes

ethanol pyridine acetic acid

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.ADDITIONwas added
2. 2
   Temperaturathe mixture was heated
3. 3
   Temperaturaunder reflux in accordance with the times
4. 4
   workup.DISTILLATIONthe solvent mixture was distilled off in vacuo
5. 5
   Extracciónthe mixture was extracted
6. 6
   OtroAfter separation of the phases
7. 7
   Extracciónthe aqueous phase was extracted twice with ethyl acetate (30 ml each time)
8. 8
   LavadoThe combined organic phases were washed with 2N HCl (50 ml)
9. 9
   Secadodried over Na2SO4
10. 10
    Concentraciónconcentrated 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
    Otrothe crystallization to completion
13. 13
    FiltraciónThe solid was filtered off with suction
14. 14
    Otrodried in vacuo

Procedimiento

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.

Fuente