MWCNTs‐ZrO2 as a reusable heterogeneous catalyst for the synthesis of N‐heterocyclic scaffolds under green reaction medium

Abstract

A simple, efficient, and facile heterogeneous multi‐walled carbon nanotubes‐zirconia nanocomposite (MWCNTs‐ZrO2) has been synthesized using natural feedstock coconut juice (água‐de‐coco do Ceará). The synthesized catalyst was characterized by Fourier transform infrared spectroscopy, X‐ray diffraction, field emission scanning electron microscopy, and X‐ray photoelectron spectroscopy analysis. The heterogeneous nanocomposite has been used for one‐pot synthesis of various N‐heterocyclic compounds like pyrazoles, 1,2‐disubstituted benzimidazoles, 2‐arylbenzazoles, and 2,3‐dihydroquinazolin‐4(1H)‐ones under green reaction medium at room temperature. This novel method has several advantages, such as short reaction time, simple work‐up, excellent yield, and green reaction conditions. The catalyst was recycled up to four times without significant loss in catalytic activity.