Synthesis of Quinoxaline Derivatives Using Heteropoly-11-Molybdo-1-Vanadophosphoric Acid Supported on Montmorillonite K10 Clay as Catalyst: A Green Approach

Abstract

The selectively new type of heterogeneous consisting of vanadium substituted polyphosphomolybdate with keggin structure H₄[PMo₁₁VO₄₀] · 32H₂O (11-molybdo-1-vanadophosphoric acid) supported on montmorillonite K10 clay (PVMo-K10). The keggin type heteropoly acid is known to possess Bronsted acidity, which is stronger than many mineral acids and then strong oxidative power. HPAK10 used as a catalyst for various syntheses of organic reactions. A green synthesis of quinoxaline derivatives from a two-component one-pot condensation reaction of substituted 1,2-dicarbonyl compounds or diacetyl and 1,2-diamines in the presence of catalyst under the solvent conditions has been described. This type of catalyst offers advantages such as shorter reaction time, excellent yield, recovery, the reaction work up is very simple and reused several times there is no change in loss of surface in catalytic activity.