Oxidation of p-xylene and methyl 4-methylbenzoate were catalyzed by transition metal Schiff-base complexes having the general formula LMCl1.2 (where M = manganese or ruthenium and L = salen, salicylaldehydeethylenediimine, saloph, salicylaldehyde-o-phenylenediimine and EDTA, ethylenediaminetetraacetate) at 150 degreesC and 500 psig air and gave p-toluic acid (> 85 %) and monomethyl terephthalate (> 70%) as the major oxidation products, respectively.