Síntese eficiente de 3-sulfenil-indóis empregando peróxido de hidrogênio-ureia (UHP)

Abstract

In the present work, a new methodology was demonstrated for the preparation of 3- sulphenyl-indoles using the oxidant urea-hydrogen peroxide (UHP) in the reaction medium. The functionality of this method is of great importance from a chemical point of view, because it allows the sulphenylation of the indole nucleus in an efficient, safe and environmentally appropriate way, as well as from a pharmaceutical point of view, since this molecule is related to several biological properties. It is noteworthy that one of the objectives of organic synthesis is the preparation of molecules with biological potential and the analysis of methodologies for the preparation. Furthermore, the use of UHP as an alternative oxidizing agent to hydrogen peroxide is of great interest, since it is a solid reagent, easy to prepare, environmentally suitable and commercially available. In order to optimize the best reaction condition, the synthesis of 3-sulphenyl- indole was carried out through the reaction of diphenyl disulfide with indole, in a medium containing UHP and molecular iodine as an additive, at room temperature. With the best reaction condition selected, the methodology was applied to obtain a series of 3-sulphenyl-indoles, with structural variation in both indole and disulfide, at different time intervals, depending on the substrate used. After the experiments were carried out, a reaction mechanism of the developed methodology was proposed.