Sustainable synthesis of [1]benzopyran azo dyes using CuCr₂O₄ NPs

Abstract

In this study, copper chromite nanoparticles (CuCr 2 O 4 NPs) were prepared by a simple hydrothermal method. This nanomaterial was found as an efficient heterogeneous catalyst for the synthesis of a new class of [1]benzopyran azo dyes via pseudo-three-component reaction of (E)-1,2-diphenyl-1-diazene with 4-hydroxycoumarin in the ratio 1:2. The aim of the present work was to provide a practical and high yielding protocol that offers several advantages such as simple procedure with an easy work-up, mild reaction conditions, and the use of CuCr 2 O 4 NPs as an efficient and easily recoverable catalyst.