Synthesis of Some Novel 3-Substituted Indole Derivatives Using Polyamine Functionalized Heterogeneous Catalyst.

In present work, we have described the use of polyamine solid supported GN3 as catalyst in organic transformations using 1H-indole-3-carbaldehyde. To the best of our knowledge, reports for the synthesis of chromen substituted at 3C position of indole are extremely rare in the literature. The polyamine functionalized immobilized silica (GN3) was found to be an excellent catalyst for synthesis of novel 2-amino-4-(1H-indol-3-yl)-5-oxo-4,5-dihydropyrano[3,2-c]chromene-3-carbonitrile derivatives and Knoevenagel condensation. Catalyst GN3 was able to furnish excellent yield for a wide range of products. Moreover, the catalyst was reusable and reused for several times without loss of its catalytic activity.