Fused Quinoline Heterocycles IX: First Example of a 3,4-Diamino-1H-pyrazolo[4,3-c]quinoline and a 3-Azido-1H-1,2,4,5,6,6a-hexaazabenzo[a]indacene

Abstract

4-Alkylamino-2-chloroquinoline-3-carbonitriles 4a - c react with NaN3 to give the corresponding tetrazolo[1,5-a]quinoline-4-carbonitriles 5a - c which are converted into 2-amino-quinoline-3-carbonitriles 8a - c by reaction with PPh3 via an iminophosphorane and subsequent hydrolysis. On the other hand, the new 3,4-diamino-1H-pyrazolo[4,3-c]quinoline (11) was prepared by fusion of the aminoquinolines 8a - c with hydrazine hydrate. Diazotization of 11 followed by reaction with NaN3 yielded the novel tetracyclic ring system 3-azido-1H-1,2,4,5,6,6a-hexaazabenzo[a]indacene (13)

Unexpected Reactions of Azido-p-Benzoquinone Derivatives towards Lawesson’s Reagent & Molecular Docking Study as a promising anticancer agent

“…In recent years, the organic azides photochemistry studies have focused on the potential of their use in "click" reactions. These reactions have been recognized to increase the molecular complexity by bringing together two molecules together in a reliable and stereoselective fashion [9][10][11][12][13]. In addition, azide derivatives yields novel transformations that have emerged and have been widely applied in organic synthesis [14].…”

A Novel Synthesis of 1‐Aryl‐6‐bromo‐3‐(5‐ethylthio‐4‐phenyl‐4H‐1,2,4‐triazol‐3‐yl)‐1H‐pyrazolo[4,3‐b]quinolin‐9(4H)‐ones via Thermal Cyclization of 4‐Azidopyrazoles

“…Nevertheless, among the isomeric pyrazolo[3,4‐ b ]quinolines, effective optical bleaches and substance possessing a broad spectrum of biological activity have been found. Prompted by the a foresaid biological and pharmaceutical activities and in continuation of our previous work aimed at developing new, simple and efficient approaches for the synthesis of poly functionally substituted heterocycles containing pyrazole or 1,2,4‐triazole nucleus with potential biological activity , we now present the first synthetic entry to the novel pyrazolo[4,3‐ b ]quinolin‐9‐ones via thermal cyclization of 4‐azidopyrazoles. To the best of our knowledge, no similar strategy for the synthesis of pyrazolo[4,3‐ b ]quinolin‐9‐one skeleton has previously been reported.…”