Collect. Czech. Chem. Commun. 1994, 59, 2447-2453

The Role of Hydrogen Peroxide in Dioxygen Induced Hydroxylation of Salicylic Acid

Kamil Lang, Dana M. Wagnerová and Jiřina Brodilová

Institute of Inorganic Chemistry, Academy of Sciences of the Czech Republic, 160 00 Prague 6, Czech Republic


The photochemically initiated oxidation of salicylic acid by molecular oxygen in the presence of [Fe(C2O4)3]3- leads to a mixture of 2,3- and 2,5-dihydroxybenzoic acids. Iron(II) generated by the photoreduction is reoxidized by dioxygen. Hydrogen peroxide formed in this reaction takes part in the Fenton reaction in the presence of Fe(II). Experiments with OH. radical scavengers document the role of the radicals in the photochemical and thermal hydroxylation of salicylic acid.