Green synthesis of quinoxaline derivatives under solvent-free conditions using recyclable tungstophosphoric acid included in zirconia

ALEXIS SOSA; TOA RIVERA; GUSTAVO ROMANELLI; LUIS PIZZIO; MIRTA BLANCO

Foz do Iguaçu

Conferencia; 4th International IUPAC Conference on Green Chemistry; 2012

IUPAC, Sociedade brasileira de química, Universidade federal de Sao Carlos

Quinoxaline derivatives are a very important class of nitrogen-containing heterocycles as they constitute useful intermediates in organic synthesis. This structure plays an important role for the design of a number of heterocyclic compounds with different biological activities. The most used method to the quinoxaline preparation is the condensation of a 1,2-dicarbonylic compound with a 1,2-diamino compound1. In this communication a green, simple and fast procedure is reported, which was developed for the preparation of quinoxaline derivatives by condensation of different 1,2-diamines and 1,2-dicarbonyl compounds, in the presence of zirconia modified with tungstophosphoric acid (PW12ZrO2) as a heterogeneous catalyst, in a solvent-free medium using conventional heating.