Magnetically separable MnFe2O4 nano-material: an efficient and reusable heterogeneous catalyst for the synthesis of 2-substituted benzimidazoles and the extended synthesis of quinoxalines at room temperature under aerobic conditions

Abstract

A simple and efficient protocol has been developed for the synthesis of biologically relevant 2-substituted benzimidazoles and quinoxalines using magnetically separable manganese ferrite (MnFe 2 O 4 ) nanopowder for the first time as a reusable heterogeneous catalyst at room temperature under aerobic conditions. MnFe 2 O 4 nanoparticles were prepared by a simple sol-gel method using starch as a bio-polymeric matrix, and characterized by XRD, TEM, EDAX and VSM analyses.

Deactivation of Cu3(BTC)2 in the Synthesis of 2-Phenylquinoxaline

“…Furthermore, it can be reused in consecutive cycles. Quinoxaline is one of the nitrogen containing heterocycles that has been synthesised using many homogeneous Lewis acid [24] catalysts, Brönsted acid [25] catalysts and heterogeneous solid catalysts [26][27][28].…”

Magnetically Separable Transition Metal Ferrites: Versatile Heterogeneous Nano‐Catalysts for the Synthesis of Diverse Bioactive Heterocycles

“…[110] They utilized this efficient, heterogeneous, reusable nano-catalyst for the synthesis of diverse heterocycles. [110][111][112][113] In 2013, they developed a simple, efficient and practical method for the synthesis of a series of biologically interesting coumarin and uracil fused pyrrole derivatives (91,92) via one-pot three-component heteroannulation reaction of 4-aminocoumarin (90) or 6-aminouracil (68), aromatic aldehydes (1) and nitromethane (15) using a catalytic amount of synthesized nano-CuFe 2 O 4 in water at 70°C (Table 29). [110] The catalyst was recycled for six cycles with almost unaltered catalytic activity.…”

Ultrasound and Nano‐Catalysts: An Ideal and Sustainable Combination to Carry out Diverse Organic Transformations

“…Benzimidazoles possess significant pharmacological efficacies that include antiviral, antibacterial, antiprotozoal, anti‐inflammatory, antimalarial, anticancer etc activities. A number of methods reported for the synthesis of benzimidazoles employing various catalysts such as polyaniline‐sulfate, nano‐In 2 O 3 , Zn 2+ ‐K10‐clay, TiCl 3 .OTf, nano‐MnFe 2 O 4 , NaY‐zeolite, Fe(HSO 4 ) 3 , MgCl 2 .6H 2 O etc . Longer reaction times (generally 2–24 h), moderate yields and the use of organic solvents such as MeOH, MeCN, CH 2 Cl 2 , CHCl 3 , DMF etc are some of the major demerits of these reported protocols.…”