5-Chloro-indole preparation
AssigneeRutgerswerke Aktiengesellschaft
InventorsManfred Maurer, Winfried Orth, Werner Fickert
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Abstract
An improved process for the preparation of 5-chloro-indole comprising reacting indoline in a chlorine-inert organic solvent with an acylating agent of an organic carboxylic acid to obtain the corresponding 1-acyl-indoline, reacting the latter in the presence of water and a basic agent with chlorine to form 5-chloro-1-acyl-indoline, subjecting the latter to saponification to obtain 5-chloro-indoline and reacting the latter in a water-immiscible organic solvent by heating with an aromatic nitrocompound in the presence of a finely powdered ruthenium catalyst to form 5-chloro-indole in excellent yields.
Claims10
A process for the preparation of 5-chloro-indole comprising reacting indoline in a chlorine-inert organic solvent with an acylating agent of an organic carboxylic acid to obtain the corresponding 1-acyl-indoline, reacting the latter in the presence of water and a basic agent with chlorine to form 5-chloro-1-acyl-indoline, subjecting the latter to acid or alkaline saponification to obtain 5-chloro-indoline, and reacting the latter in a water-immiscible organic solvent by heating with an aromatic nitrocompound in the presence of a finely powdered ruthenium catalyst to form 5-chloro-indole.
Dependencies are inferred from the claim text.