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Novel Azo-fused Dipyrazolopyridine Derivatives using Waste Orange Peel-derived C-SO3H Nanopowder as an Efficient and Reusable Catalyst

Nagarajan Nagasundaram, Department of Chemistry, Periyar University, Salem, TN, India. Sivagiri Sumitha, Department of Chemistry, Periyar University, Salem, TN, India. Appaswami Lalitha lalitha2531@yahoo.co.in
Department of Chemistry, Periyar University, Salem, TN, India.

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Abstract

A new series of structurally diverse azo-fused dipyrazolopyridines has been synthesized via one-pot pseudo-six-component reaction of various substituted aryl azo-salicylaldehydes with ethyl acetoacetate, hydrazine hydrate and ammonium acetate, using waste orange peel-derived carbon modified sulfonic acid (C-SO₃H) as a mild, efficient and inexpensive heterogeneous catalyst. The prepared catalyst was characterized by FT-IR, XRD, SEM, EDX and XPS studies. The catalytically synthesized compounds were characterized by FT-IR, ¹H NMR and ¹³C NMR. The notable advantage was the use of a recyclable powder catalyst (C-SO₃H) for excellent yields and rapid formation of the desired azo-fused dipyrazolopyridines with a simple work-up procedure.

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Reference

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