KO<i>t</i>Bu‐Mediated Aza‐Michael Addition of Aromatic Amines or <i>N</i>‐Phenylurea to 3‐Nitro‐2‐phenyl‐2<i>H</i>‐chromenes and Sequential Aerobic Dehydrogenation

Abstract

A highly efficient KO t Bu‐mediated aza‐Michael addition of aromatic amines and/or N ‐phenylurea derivatives to 3‐nitro‐2‐phenyl‐2 H ‐chromenes and sequential aerobic dehydrogenation is reported. This method provides a novel protocol for C–N bond formation in 3‐nitro‐2‐phenyl‐2 H ‐chromenes under cost‐effective and operationally convenient conditions. A wide range of 4‐(phenylamino)‐3‐nitro‐2‐phenyl‐2 H ‐chromenes have been synthesized in good‐to‐high yields (68–86 %) at 35–40 °C within 5–10 minutes.