A Convenient One‐Pot Synthesis of Triazolopyridine and Related Heterocycle Fused‐Triazole Analogs Through Copper Catalyzed Oxidative Cyclization Strategy

Abstract

One‐pot synthesis of heterocycle fused‐triazole analogs from the corresponding aldehydes and heteroarylhydrazines is demonstrated. Transformation of hydrazones to the desired systems was achieved by employing the oxidative cyclization with catalytic CuBr2 and oxone. This reaction condition is mild and selective, and a wide range of functional groups were able to sustain. An array of biologically important triazolopyridines, triazolopyridazines, triazolopyrimidines, and triazoloquinolines were obtained in fairly good yield.

Recent Synthetic and Biological Developments on 1,2,4‐Triazolopyrimidines

“…The obtained can be applied to a readily available aryl (excluding halogencontaining) as well as alkyl aldehydes (Scheme 54). [114] Mei-Lin Tang and co-workers demonstrated access to 5-(5amino-2-(heteroaryl)- [1,2,4] ). [115] Shefali Chowdhary and co-workers reported triazolopyrimidine and 4-aminoquinolines as potent antiplasmodial agents.…”

Antibacterial Activity of Quinoline‐Based Derivatives against Methicillin‐Resistant Staphylococcus aureus and Pseudomonas aeruginosa: Design, Synthesis, DFT and Molecular Dynamic Simulations

“…Compounds 3, 5, 8, 10, and 12 were previously prepared. [67][68][69] The characterization data of all the newly synthesized compounds are available as supplementary information.…”

Recent Advances in the Oxone-Mediated Synthesis of Heterocyclic Compounds

“…In 2015, Nagarajan and co-workers reported the synthesis of triazole-fused heterocycles 3 through a one-pot strategy, starting from aldehydes 4 and heteroarylhydrazines 5. The reaction involves the formation in situ of the hydrazone A, which in the sequence is submitted to an Oxone/CuBr-mediated intramolecular oxidative cyclization (Scheme 4) [16]. Through this simple and selective system, several substituted aldehydes bearing a wide range of functional groups were employed as substrate, affording a diversity of triazolefused pyridines, pyridazines, pyrimidine and quinolines 3, in good yields and short reaction times.…”