Abstract

In this article, Tributyl hexadecyl phosphonium bromide (TBHDPB) supported on 4-pyridine carboxylic acid functionalized Fe3O4 nanoparticles was synthesized, via coprecipitation of Fe2+ and Fe3+ with ammonium hydroxide. The surface of synthesized nanoparticles was organically functionalized by commercially coupling agent namely, 4-pyridinecarboxylic acid (PCA) and then reaction of this prepared Fe3O4-PCA magnetite nanoparticles with TBHDPB at reflux temperature afforded the desired product. The prepared catalyst TBHDPB supported on Fe3O4-PCA nanoparticles was characterized using Powder X-ray diffraction analysis (XRD), Fourier transforms infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and Energy Disperaive X-Ray Analysis (EDX). The prepared nanocatalyst was examined as a new and efficient catalyst for the synthesis of benzimidazole derivatives at reflux a under solvent-free conditions.

INTRODUCTION

Magnetic nanoparticles (MNPs) and their multifunctionalized counterparts have attracted great interests because of their potential applications in high-density data storage, biochemistry, hyperthermia, drug delivery and MR contrast reagent (1–7). Magnetic nanoparticles have the well-developed surface chemistry, it allows loading of a range of functionalities onto their surfaces and can be easily separated and recycled from the products by an external magnet. This kind of separation prevents the loss of solid catalyst in the process and is not time-consuming. It also enhances products purity and optimizes operational costs (8–11).

TBHDPB can be used as a lewis acid catalyst for different kind of reactions. In modern chemical research, catalyst and catalytic reactions are always attracting more attention in fundamental and industrial applications, therefore, for the development of efficient and new synthetic method for preparation nanoparticles support, because of their good stability, easy synthesis and functionalize, high surface area and magnetic decantation, we suggested the preparation of Fe3O4-PCA-TBHDPB nanocatalyst. At first, Magneti ...