<p>Thiazole-5-ones were synthesized using a novel and efficient one-pot three-component reaction involving acetophenones and/or aromatic aldehyde derivatives, ethyl chloroacetate and thiosemicarbazide, facilitated by a newly reported heterogeneous nanocatalyst formulated as Fe₃O₄/cellulose/Zn-MOF. This protocol yielded the desired products with excellent yields (90–98%) during a simple procedure in the absence of solvent within brief reaction times (10–15&#xa0;min). The nanocatalyst was easily recovered using an external magnet and retained high catalytic efficiency over five consecutive cycles. The structural integrity of the recovered catalyst was confirmed by FT-IR and XRD analysis, demonstrating its potential for sustainable and green chemical transformations. The combination of high efficiency, excellent product yields, straightforward work-up, catalyst recyclability, and solvent-free conditions highlights the potential of the Fe₃O₄/cellulose/Zn-MOF nanocatalyst as a practical and sustainable catalytic system for the synthesis of thiazole-5-one derivatives. The structure of the synthesized heterogeneous catalyst was thoroughly characterized using various spectroscopic techniques including SEM, TEM, XRD, EDX/Mapping, VSM, TGA, and FT-IR.</p> Graphical Abstract <p></p>