High-yielding regioselective synthesis of p-quinone fused 5-substituted-1,4-benzodiazepine scaffolds via Pictet–Spengler type cycloannulation.

We designed a robust and efficient greener synthetic protocol to access p-quinone fused 5-substituted-1,4-benzodiazepine scaffolds, a new molecular hybrid, through InCl3 mediated Pictet–Spengler type cycloannulation of 2-amino-3-arylamino-p-quinone and commercially prevalent aldehydes. This protocol would ease access to privileged redox-active p-quinone fused seven-membered frameworks that are difficult to access by other protocols and would find potential applications in biological and electrochemical research. [ABSTRACT FROM AUTHOR]