The present research work deals with the green synthesis of substituted pyrazolone derivatives 4(a–f) from 2,4-dinitrophenylhydrazine with various substituted aromatic aldehyde and ethyl acetoacetate in the presence of silica-supported zinc chloride (SiO2/ZnCl2) as a recyclable Lewis acid catalyst. The synthesized compounds were structurally characterized with IR, 1H NMR, Mass spectra and elemental analysis. All these compounds were tested for their antioxidant activity by using the DPPH radical scavenging method.
