Efficient Non-catalytic Oxidation of ۱,۵-Dihydroxynaphthalene with Iodosylbenzene in Water and the Presence of Polyvinylpyrrolidone

Non-catalytic oxidation of ۱,۵-dihydroxynaphthalene as an organic water pollutant phenolic compound to Juglonewith iodosylbenzene in the presence of a water-soluble polymer and a short reaction time is reported.Hypervalent iodine(III) reagents as environmentally friendly reagents have found many applications in oxidativetransformations of organic compounds. However, the polymeric structure of iodosylbenzene and most otherhypervalent iodine(III) compounds, significantly decreases their reactivity towards the oxidation of organicsubstrates.[۲] In continuing our studies on hypervalent iodine compounds, [۳,۴] herein the synthesis of a nearly watersoluble analogue of iodosylbenzene from iodobenzene diacetate or pre-synthesized non-soluble iodosylbenzene inthe presence of polyvinylpyrrolidone is reported. The oxidant was used as an efficient reagent for direct, quatitativeoxidation of ۱,۵-dihydroxynaphthalene to Juglone in water, under mild conditions and a reaction time of ca. ۳۰ min.UV-vis spectrophotometry at the λmax of ۱,۵-dihydroxynaphthalene (۳۰۱ nm, ε = ۷۶۶۴ M-۱cm-۱) or Juglone (۴۲۷ nm.ε = ۳۸۱۱ M-۱cm-۱) was used for monitoring the progress of the oxidation reaction. It is noteworthy that in most ofprevious studies, the oxidation of organic compounds with iodosylbenzene was conducted using different transitionmetal complexes as the catalysts. [۵-۷]Presence of PolyvinylpyrrolidoneZakavi*as an organic water pollutant phenolic compoundwater-soluble polymer and a short reaction time is reported.many applicationcompounds.[۱] However, the polymeric structure of iodosylbenzene and most other, hypervalent iodine compounds, [۳,۴] herein the synthesis of a nearly waterdiacetate or pre-synthesized non-soluble