Waste-Derived Iron Nanoparticles for Solvent-Free Single-Step Reductive Acetylation of Nitroarenes

A simple and single-step synthetic protocol is reportedhere forsynthesizing medicinally important amide compounds such as acetanilide(N-phenylacetamide) and its derivatives (includingparacetamol and phenacetin). Compared to the existing reports usedfor a single-step amidation that requires multiple reagents, herein,waste-derived iron nanoparticles (FeO x -NPs) isolated from the "free-of-cost available iron dust/powder"were used for the same single-step amidation reaction without usingany external reagents and high pressure, resulting in the cost-effectiveviable reported procedure. The Soxhlet-purified iron dust is subjectedto high-temperature heating at similar to 800 degrees C in a muffle furnaceto achieve its heterogeneously active form (Fe3O4-type moieties on its surface). The as-prepared catalyst (FeOx-NPs) has been used to synthesize 17 acetanilide derivativesincluding two essential antipyretic drugs, paracetamol and phenacetin,on a gram scale, and one industrially important dye/pigment precursor(2-nitroacetanilide). Based on the X-ray photoelectron spectroscopyand vibrating sample magnetometry results, a possible mechanism hasbeen proposed. The sustainability associated with the whole processis the direct amide formation using a magnetically separable waste-derivedmetal catalyst in solvent-free conditions, which provides a possibleway to utilize large-scale industrial waste, thus directly reducingsome environmental stress. Asustainable approach of utilizing iron powder/dust wastefor reagent and solvent-free one-step reductive amidation of nitroarenes.