Selective catalytic oxidation of naphthol to 2-hydroxyl-1,4-naphthoquinone by hydrogen peroxide over metalloporphyrin catalysts

Abstract The reactions of 1-naphthol and 2-naphthol were catalytically converted into 2-hydroxyl-1,4-naphthoquinone (HNQ, lawsone) in the presence of H 2 O 2 over metalloporphyrin catalysts. The catalytic data showed conversion at 57% and single product of lawsone, which were investigated by UV–Vis, IR, NMR, MS, mp determination, and element analysis. Influences of solvents, amounts of NaOH, H 2 O 2 , and metalloporphyrins, as well as temperature in the catalytic reaction, were carried out, and a proposed catalytic mechanism based on UV–Vis and EPR measurements was discussed.