Tandem Blaise-Nenitzescu reaction: One-pot synthesis of 5-hydroxy-α-(aminomethylene)benzofuran-2(3H)-ones from nitriles

Abstract

In contrast to the reaction of benzoquinones with β-enaminoesters providing indoles (Nenitzescu reaction), the tandem one-pot reaction of the Blaise reaction intermediate, zinc bromide complex of β-enaminoesters, with benzoquinone affords 5-hydroxy-α-(aminomethylene)benzofuran-2(3H)-ones in good to excellent yields (tandem Blaise-Nenitzescu reaction). © The Royal Society of Chemistry 2011.