The study of catecholase activity of a series of Schiff base compounds using in situ copper complexes of 4-hydroxy-6-methyl-3-(1-(phenylimino)ethyl)-2H-pyran-2-one derivatives has been reported. The reaction rate depends on four parameters: The nature of the substitution in para position to the benzene ring, the nature of counter anion, the concentration of ligand and the nature of solvent. The highest