Selenilação de imidazo-[1, 2–a]-piridinas mediada por peróxido de hidrogênio-uréia em lactato de etila: um processo ambientalmente adequado.

Abstract

The advancement of ecologically sustainable approaches has emerged as one of the fastestgrowing areas in recent scientific research. Developing new methodologies through the adaptation of established techniques in the field represents a stimulating challenge for researchers. The present work aims to develop a greener methodology for the selenylation of imidazo-[1,2-a]-pyridines, using urea hydrogen peroxide, a non-toxic, stable, and cost-effective oxidizing agent, in ethyl lactate, a solvent derived from biomass. Through the optimization of reaction conditions, ethyl lactate was determined as the solvent of choice, with an optimal temperature of 60 °C, a reaction time of 3 hours, and a stoichiometric amount of urea hydrogen peroxide (UHP) of 1 equivalent. Subsequently, a scope was constructed with 7 examples of imidazo-[1,2-a]-pyridines showing good yields, confirming the effectiveness of the methodology. Additionally, control experiments were conducted to study the mechanism. Thus, it was possible to develop an efficient and more sustainable synthetic route for the selenylation of these compounds.