Synthesis of Benzidine Derivatives via FeCl₃·6H₂O‑Promoted Oxidative Coupling of Anilines

Abstract

Under open-flask conditions in the presence of commercially available FeCl₃·6H₂O, N,N-disubstituted anilines can be converted into diversely functionalized benzidines with yields of up to 99%. Oxidative coupling was extended to N-monosubstituted anilines, and the method was applied to the efficient preparation of 6,6′-biquinoline. Mechanistic investigations have also been performed to explain the observed reactivities