One-pot synthesis of [1,2,3]triazole-fused pyrazinopyridazindione tricycles by a 'click and activate' approach

Substituted [1,2,3]triazole-fused pyrazinopyridazindione tricycles were synthesized in a four-component, stepwise condensation. The key step in this one-pot process was a thermal [3+2] triazole formation which activated the adjacent position and set the stage for a subsequent tandem nucleophilic aromatic substitution/cyclization sequence.