Aluminium Chloride–Catalyzed Synthesis of 4-Benzyl Cinnolines from Aryl Hydrazones

Abstract

An efficient synthesis of 4-benzyl cinnolines from aryl phenylallylidene hydrazone is described. In this report aluminium chloride as a Lewis acid catalyst and toluene as a solvent are used for the synthesis. This method is expected to more advantageous than the other reported methods of synthesis of the cinnoline rings because of its low cost, better yield, and benign reaction conditions.

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GRAPHICAL ABSTRACT

Keywords:

• Aluminium chloride
• aryl hydrazones
• 4-benzyl cinnolines

ACKNOWLEDGMENTS

The authors are grateful to K. Mohan Rao, head of the Sophisticated Analytical Instrument Facility (SAIF), Northeastern Hill University (NEHU), Shillong, for NMR and mass spectroscopy support of this research and CIF of Tezpur University. We thank S. K. Bhattacharjee, Department of Chemistry, Gauhati University, Guwahati, Assam, India, for valuable suggestions.

Notes

^a Isolated yield of 2.

^a Isolated yield of 3.

^a Isolated yield of 3a.

^a Isolated yield of 3a.