Reaktion #6324

Reaktionsgleichung

Magnesium

ethyl indole-2-carboxylate

ammonium hydroxide

magnesium

→

title compound

(±) Methyl indoline-2-carboxylate

Lösungsmittel

methanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigethe mixture is placed in an ice bath
2. 2
   Sonstigekept below 45°
3. 3
   Sonstigeis 7°
4. 4
   ExtraktionThe mixture is then extracted with methylene chloride (3 x)
5. 5
   TrocknenThe combined organic layers are dried over magnesium sulfate
6. 6
   Einengenconcentrated

Vorschrift

Magnesium turnings (3.60 g) are added to a mixture of ethyl indole-2-carboxylate (I, Aldrich Chemical, 13.963 g) in methanol (200 ml). After evolution of gas has started, the mixture is placed in an ice bath and the temperature kept below 45°. After 4.5 hours all of the magnesium is used up and the temperature is 7°. At this time the mixture is added to ice cold hydrochloric acid (3N, 120 ml). The acidic mixture is then made alkaline (pH 10) with ammonium hydroxide (3N). The mixture is then extracted with methylene chloride (3 x). The combined organic layers are dried over magnesium sulfate and concentrated to give the title compound.

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