Sulfonated Ethylenediamine Functionalized Magnetic Nanoparticles as a Highly Efficient Heterogeneous Nanocatalyst for the Green Synthesis of 2,3-Dihydroquinazolin-4(1H)-ones

Abstract

In the present study, a new magnetically recyclable nanocatalyst, Fe3O4@SiO2@(CH2)3-en-SO3H/H2SO4, was prepared through the immobilization of sulfonated ethylenediamine on the silica-coated magnetite nanoparticles. The catalyst was fully characterized by several physicochemical techniques, including FT-IR, FESEM, TEM, EDS, VSM, XRD and TGA. The resultant nanocatalyst was then utilized in the green synthesis of 2,3-dihydroquinazolin-4(1H)-ones via the cyclocondensation reaction of various aldehydes and ketones with anthranilamide in refluxed EtOH. Short reaction times, high product yields, environmentally friendly reaction conditions, simple operation and reusability of the catalyst are important features of the present procedure. The catalyst can magnetically be recycled and reused several times without notable loss in activity.

Nanocatalyzed Synthesis of Benzoxazoles

“…The catalyst performed excellently and can be easily removed from the reaction medium and used repeatedly without suffering a major loss in catalytic properties. [54] In 2019, H. Sharghi and colleagues successfully investigated the use of α-amino acids (51) as non-toxic and affordable substitutes for aliphatic amines (50), in the formation of benzoxazole compounds (52) using a carbon (aryl)-hydroxyl functionalization of catechol derivatives (49) in the presence of a nanomagnetic Fe 3 O 4 catalyst (NM-Fe 3 O 4 Table 1, Entry 11) in H 2 O/ethanol as a safe reaction medium (Scheme 15). The produced compounds were identical to common amines, which is a substantial benefit of this approach.…”

“…Moderate reaction conditions, simple set‐up, excellent yield, and environmentally friendly features such as avoiding toxic organic solvents, harmful catalysts, and waste seem to be a few of the advantageous aspects present in this protocol. The catalyst performed excellently and can be easily removed from the reaction medium and used repeatedly without suffering a major loss in catalytic properties [54] …”