Reaction of isatins with active methylene compounds on neutral alumina: Formation of knoevenagel condensates and other interesting products

Abstract

Isatin and its N-methyl and 5-nitro derivatives underwent smooth reaction with a variety of acyclic and cyclic active methylene compounds on neutral alumina at rt to efficiently furnish Knoevenagel condensates in the majority of the cases and tandem Knoevenagel condensation-Michael addition products including spiro compounds in two cases. © 2009 The Japan Institute of Heterocyclic Chemistry All rights reserved.