Reaktion #1696575

Reaktionsgleichung

p-toluenesulfonic acid

isopropyl 1-methyl-3-indoleacetimidate hydrochloride

triethylamine

1-methyl-3-indolylglyoxylic acid

triethylamine

isobutyl chloroformate

→

3,4-bis-(1 -methyl-3-indolyl)-1H-pyrrole-2,5-dione

Ausbeute 30.0%

Lösungsmittel

dichloromethane

dichloromethane

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe solution obtained
2. 2
   Temperaturwas heated
3. 3
   Temperaturto reflux under nitrogen for 18 hours
4. 4
   Temperaturcooled
5. 5
   workup.WAITAfter 1 hour
6. 6
   Sonstigethe solvent was removed under reduced pressure
7. 7
   Sonstigethe residue was purified by flash chromatography on silica gel
8. 8
   Waschenfor the elution

Vorschrift

A stirred solution of 406 mg (2 mmol) of 1-methyl-3-indolylglyoxylic acid in 20ml of dichloromethane was treated with 202 mg (2 mmol) of triethylamine and 273 mg (2 mmol) of isobutyl chloroformate. After 0.5 hour, the solution was added dropwise to a stirred solution of 533 mg (2 mmol) of isopropyl 1-methyl-3-indoleacetimidate hydrochloride and 808 mg (8 mmol) of triethylamine in 50 ml of dichloromethane. The solution obtained was heated to reflux under nitrogen for 18 hours, cooled and treated with 1.9 g (10 mmol) of p-toluenesulfonic acid. After 1 hour, the solvent was removed under reduced pressure and the residue was purified by flash chromatography on silica gel using dichloromethane/ethyl acetate (8:1) for the elution to give 107 mg(30% ) of 3,4-bis-(1 -methyl-3-indolyl)-1H-pyrrole-2,5-dione in the form of an orange colored solid of melting point >310° C.

Quelle