Elegant One-Pot Synthesis of Quinolino[2′,3′:7,6]-cyclohept[1,2-b]indole Through Friedländer and Pfitzinger Annulation Reaction

Abstract

A rapid, simple, and efficient method for the preparation of various quinolino[2′,3′:7,6]cyclohept[1,2-b]indoles has been developed through the Friedländer and Pfitzinger condensations of 1-oxo-cyclohept[b]indole with o-amino benzophenone and isatin respectively. Reactions were performed by under different reaction conditions.

Keywords:

• Friedländer synthesis
• Pfitzinger synthesis
• p-TsOH
• quinolino[2′,3′:7,6]cyclohept[1,2-b]indoles

ACKNOWLEDGMENTS

Our sincere thanks go to the chairman, NMR Research Centre, IISc, Bangalore, SAIF, IIT Madras, Chennai, and the director, ISO Quality Assurance Cell, Indian Institute of Chemical Technology (IICT), Hyderabad, for providing access to their NMR and mass spectral facilities. The x-ray diffractometer was funded by NSF Grant 0087210, Ohio Board of Regents Grant CAP-491, and Youngstown State University.