Efficient Synthesis of Benzodiazepino and Pyrazino Carbazoles

Abstract

An efficient method for the synthesis of benzodiazepino and pyrazino-annelated carbazoles by the facile reaction of 2,3,4,9-tetrahydro-1H–carbazol-1-one with anthranilic acid, 3-aminopyrazine-2-carboxylic acid, and glycine catalyzed by polyphosphoric acid has been carried out.

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GRAPHICAL ABSTRACT

Keywords:

• 3-Aminopyrazine-2-carboxylic acid
• anthranilic acid
• glycine
• polyphosphoric acid
• 2,3,4,9-tetrahydro-1H–carbazol-1-one

ACKNOWLEDGMENTS

The authors thank the Indian Institute of Science, Bangalore, Indian Institute of Technology Madras, Chennai, for NMR and Indian Institute of Chemical Technology, Hyderabad, for mass spectral data.