Succinimide-N-sulfonic acid as an efficient recyclable catalyst for the synthesis of some fused indolo pyrano pyrimidinone derivatives

S S Mansoor,K Logaiya,K Aswin,S P N Sudhan

doi:10.4314/bcse.v29i3.14

Abstract

A new, simple, thermally efficient and solvent-free condensation of 2-amino-4,5-dihydro-4-phenylpyrano[3,2-b]indole-3-carbonitrile derivatives with coumarin-3-carboxylic acid employing succinimide-N-sulfonic acid (SuSA) as catalyst for the synthesis of a series of 5,6-dihydro-2-(2-oxo-2H-chromen-3-yl)-5-phenyl-indolo[2',3':5,6]pyrano[2,3-d]pyrimidin-4(3H)-one derivatives is described. This method has the advantages of high yield, simple methodology, and short reaction time, as well as being green in terms of avoiding the use of toxic catalysts and solvents. Furthermore, the catalyst could be recycled and reused four times without significant loss of activity. Thiourea dioxide (TUD) catalyzed efficient three-component coupling reactions of aromatic aldehydes, 3-hydroxyindole and malononitrile in water at 70 ºC was described as the preparation of 2-amino-4,5-dihydro-4-phenylpyrano[3,2-b]indole-3-carbonitrile derivatives. KEY WORDS: Succinimide-N-sulfonic acid, Thiourea dioxide, Coumarin-3-carboxylic acid, Indolo pyrano pyrimidineone derivatives Bull. Chem. Soc. Ethiop. 2015, 29(3), 457-471.DOI: http://dx.doi.org/10.4314/bcse.v29i3.14

Highlights

Coumarins are secondary heterocyclic metabolites composed of fused benzene and α-pyrone rings, and they occur widely in different parts of plants, such as roots, seeds, nuts, flowers and fruits [1]
As part of continuing effort in our laboratory towards the development of environmentally friendly procedures for the synthesis of biologically active heterocyclic molecules [24,25,26], we describe the synthesis of 5,6-dihydro-2-(2-oxo-2H-chromen-3-yl)-5-phenyl-indolo[2',3':5,6]pyrano[2,3-d]pyrimidin-4(3H)-one derivatives from the reaction of 2-amino-4,5-dihydro-4phenylpyrano[3,2-b]indole-3-carbonitriles and coumarine-3-carboxylic acid using succinimide-Nsulfonic acid (SuSA) as an efficient reusable catalyst under solvent-free conditions. 2-Amino-4,5-dihydro-4-phenylpyrano[3,2-b]indole-3-carbonitriles were synthesized from benzaldehydes, 3-hydroxyindole and malononitrile using Thiourea dioxide (TUD) as an efficient organocatalyst (Scheme 1)
The aim of this presented protocol is to highlight the development of a new eco-compatible strategy for the synthesis of 5,6-dihydro-2-(2-oxo-2H-chromen-3-yl)-5-phenyl-indolo[2',3':5,6]pyrano[2,3-d]pyrimidin-4(3H)-ones by the condensation reaction of 2-amino-4,5dihydro-4-phenyl-pyrano[3,2-b]indole-3-carbonitrile derivatives with coumarine-3-carboxylic acid using SuSA under solvent-free conditions (Scheme 3)

Summary

Introduction

Coumarins are secondary heterocyclic metabolites composed of fused benzene and α-pyrone rings, and they occur widely in different parts of plants, such as roots, seeds, nuts, flowers and fruits [1]. As part of continuing effort in our laboratory towards the development of environmentally friendly procedures for the synthesis of biologically active heterocyclic molecules [24,25,26], we describe the synthesis of 5,6-dihydro-2-(2-oxo-2H-chromen-3-yl)-5-phenyl-indolo[2',3':5,6]pyrano[2,3-d]pyrimidin-4(3H)-one derivatives from the reaction of 2-amino-4,5-dihydro-4phenylpyrano[3,2-b]indole-3-carbonitriles and coumarine-3-carboxylic acid using SuSA as an efficient reusable catalyst under solvent-free conditions. A mixture of 2-amino-4,5-dihydro-4-phenylpyrano[3,2-b]indole-3-carbonitrile 4a-j (1 mmol), coumarin-3-carboxylic acid (1 mmol) and SuSA (0.05 mmol) were heated at 80 oC for about 3.0–4.0 h (Scheme 3).

Results

Conclusion