Tungstophosphoric acid/mesoporous silicas as suitable catalysts in quinoxaline synthesis

SOSA, ALEXIS A.; PALERMO, VALERIA; LANGER, PETER; LUQUE, RAFAEL; ROMANELLI, GUSTAVO P.; PIZZIO, LUIS R.

Molecular Catalysis

Elsevier

Año: 2022 vol. 517

2468-8231

Quinoxalines and their derivatives are of great value in the chemical and biological sciences. These compoundsare found in dyes, agrochemicals, and are used as building blocks of drugs for the treatment of different diseases.Quinoxalines and their derivatives are synthesized by a heterogeneous catalysis procedure that involves thecondensation of 1,2-dicarbonyl compounds with aromatic 1,2-diamines in an aprotic organic solvent at lowtemperature, in the presence of an acid catalyst composed of tungstophosphoric acid immobilized on mesoporoussilica nanoparticles. The reaction process is very simple and the catalyst, besides being very active and selective,can be easily isolated from the reaction medium and reused in subsequent reactions without considerable loss ofactivity. Quinoxalines are obtained in short reaction time with excellent yields and high purity.