Synthesis of Polyfunctionally Substituted Pyrazolonaphthyridine, Pentaazanaphthalene, and Heptaazaphenanthrene Derivatives

Abstract

6-aminopyrazolo[3,4-b]pyridine-5-carbonitrile (2) was used as a precursor for the synthesis of a variety of pyrazolo[3,4-b][1,8]naphthyridines (3, 4) and pentaazacyclopenta[b]naphthalenes (5–10, 13, 14) via the initial addition to either the cyano or amino group followed by cyclization. Also, a series of heptaazadicyclopenta[a,g]naphthalenes (15–17) and heptaazacyclopenta[b]phenanthrenes (18, 19) were obtained via the interaction of 4-(dibenzothiophen-2-yl)-1,5-dihydro-5-imino-3-methyl-1-phenyl-1,2,6,8,9-pentaazacyclopenta[b]naphthalen-6-ylamine (14) with different reagents. The structures of the synthesized compounds were established by elemental and spectral analyses.

Keywords:

• Heptaazacyclopenta[b]phenanthrene
• pentaazacyclopenta[b]naphthalene
• pyrazolo[3,4-b]pyridine

Acknowledgments

The author is grateful to the Botany Department, Faculty of Science, Benha University, Benha, Egypt, for biological screening.