Synthesis 2011(5): 764-768  
DOI: 10.1055/s-0030-1258422
PAPER
© Georg Thieme Verlag Stuttgart ˙ New York

Synthesis of 2-Aminoindole-3-carboxylic Acid Derivatives by the Copper(I) Iodide Catalyzed Reaction of N-(2-Iodophenyl)formamides with Malononitrile or Cyanoacetates

Kazuhiro Kobayashi*, Toshihide Komatsu, Yuki Yokoi, Hisatoshi Konishi
Division of Applied Chemistry, Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, 4-101 Koyama-minami, Tottori 680-8552, Japan
Fax: +81(857)315263; e-Mail: kkoba@chem.tottori-u.ac.jp;
Further Information

Publication History

Received 9 November 2010
Publication Date:
03 February 2011 (online)

Abstract

An efficient method for the synthesis of 2-aminoindole-3-carbonitriles and 2-aminoindole-3-carboxylates by the reaction of N-(2-iodophenyl)formamides with malononitrile and cyanoacetates, respectively, in the presence of a catalytic amount of copper(I) iodide using potassium carbonate as a base is reported.

5

Before subjection to column chromatography on silica gel, the mixture must be filtered through a small pad of neutral alumina. Omission of this filtration procedure did not give 3a in a satisfactory purity. For details, see the experimental section.