Knoevenagel Reactions of Indole-3-carbaldehyde. Synthesis of 3-Substituted Indole Derivatives

Abstract

The Knoevenagel condensations of 1H-indole-3-carbaldehyde with various CH acids gave a number of substituted 3-(1H-indol-3-yl)acrylonitriles and acrylamides which were alkylated to afford the corresponding N-alkyl derivatives. The latter were used as Michael acceptors in the synthesis of 4H-pyran, pyridine, 5,6,7,8-tetrahydroquinoline, and [1,3]thiazolo[3,2-a]pyridine derivatives containing an indole fragment.