Two approaches to a new heterocyclic system of pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidine

Mezheritsky, Valery V.; Minyarva, Lyudmila G.; Tyurin, R. V.; Krasnikov, Valery V.; Vorobyev, Eugeny V.; Starikova, Z. A.

doi:10.3998/ark.5550190.0006.a02

Cited by 4 publications

(2 citation statements)

References 8 publications

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“…Ethoxymethyleneamino derivative [19] 23 was stirred with benzohydrazide (20) [37] in the presence of absolute ethanol at room temperature and left overnight to afford the target compound 24, which was heated under reflux in N,N-dimethylformamide [39,40] for a short period to yield the corresponding fused (pyrimidine-3-4H-yl) benzamide derivative 25 as outlined in Scheme 4. The 1 H NMR spectrum of compound 24 showed two deuterium oxide exchangeable singlet signals at δ 8.08 and δ 9.77 ppm attributed to ═ CH-NH and NH-C═O protons, respectively, while the appearance of a singlet at δ 8.39 ppm attributed to the pyrimidine-C 2 proton as well as two deuterium oxide exchangeable singlet signals at δ 7.31 and 12.93 ppm corresponding to imino and amide protons, respectively, in the 1 H NMR spectrum of compound 25 confirmed the formation of the pyrimidine ring.…”

Section: Resultsmentioning

confidence: 99%

Synthesis and antitumor evaluation of some new derivatives and fused heterocyclic compounds derived from thieno[2,3‐b]pyridine: Part 2

Hassan

Sarg

El‐Sebaey

2019

Journal of Heterocyclic Chem

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As a continuation of our research on developing anticancer agents and based on the proven proprieties of thieno[2,3-b]pyridines as anticancer, we have designed to synthesize novel thieno[2,3-b]pyridine derivatives that incorporate different biologically active heterocycles through various chemical reactions.All of the newly obtained compounds, compared with the standard anticancer drug (doxorubicin), were screened in vitro for their antitumor activity against hepatocellular carcinoma (HepG-2) and human breast cancer (MCF-7) cell lines. The results revealed that compounds 3, 7, 12, and 19 were found to be the most potent against both HepG-2 and MCF-7 cell lines exhibiting IC 50 values ranging from 3.67 to 11.50 and 5.13 to 11.80 μg/mL, respectively, among which compound 7 has a more potent activity than the reference drug doxorubicin against HepG-2 cell line, showing IC 50 value of 3.67 μg/mL (doxorubicin 4.65 μg/mL).

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Section: Resultsmentioning

confidence: 99%

Synthesis and antitumor evaluation of some new derivatives and fused heterocyclic compounds derived from thieno[2,3‐b]pyridine: Part 2

Hassan

Sarg

El‐Sebaey

2019

Journal of Heterocyclic Chem

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“…4 Alternatively, dehydrative cyclization of the 4-acyl-hydrazinopyrimidines was reported to afford, after ring rearrangement, [1,2,4]triazolo [1,5-c]pyrimidines instead of the isomeric [1,2,4]triazolo[4,3-c]pyrimidines. 7 Each of the existing methods has its own merits, while sometimes they are plagued by the limitations of complex pathways, harsh conditions, difficult workup aside from the formation of side products. In view of the emerging importance of [1,2,4]triazolo [1,5-c]pyrimidine nucleus as a fertile source of biologically important molecules we wish to report our recent findings in this connection.…”

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confidence: 99%

A Convenient Route for the Synthesis of Novel 2-Substituted [1,2,4]Triazolo[1,5-c]pyrimidine Derivatives

Li¹,

Li²,

Wang³

2010

Synlett

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Reactions of easily accessible chloropyrimidinyl hydrazones with bromine were investigated. Oxidative cyclization followed by concomitant bromination led to the formation of [1,2,4]triazolo[4,3-c]pyrimidines, which then underwent the Dimroth rearrangement to afford highly functionalized 2-substituted [1,2,4]triazolo[1,5-c]pyrimidines. Pyrimidines and fused bi-or tricyclic analogues are privileged heterocycles that are of immense importance in the design and discovery of new compounds for pharmaceutical and herbicide applications. 1 In particular, compounds carrying a [1,2,4]triazolo[1,5-c]pyrimidine nucleus have received considerable attention due to their remarkable adenosine and benzodiazepine receptor affinity. 2 For example, 3-and/or 5-substituted 7H-pyrazolo[4,3-e][1,2,4]triazolo[4,3-c]pyrimidines have been reported to be potent xanthine oxidase (XO) inhibitors. 3 Many 1,2,4-triazolo[1,5-c]pyrimidines as well as pyrazolo[4,3-e][1,2,4]triazolo [4,3-c]pyrimidines have recently been prepared and investigated for use as selective antagonists at the A2a receptor, which offers great promise in the treatment of Parkinson's disease. 4 A recent paper by Clarkson and co-workers also predicted the potential use of triazolopyrimidines as inhibitors of Shiga toxin trafficking. 5 In addition, various triazolopyrimidines have been used as the new pharmacological tool for the characterization of human A 3 adenosine receptor. 6

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Synthesis, reactions, and antimicrobial activity of some novel pyrazolo[3,4‐d]pyrimidine, pyrazolo[4,3‐e][1,2,4]triazolo[1,5‐c]pyrimidine, and pyrazolo[4,3‐e][1,2,4]triazolo[3,4‐c]pyrimidine derivatives

Hassaneen

Saleh

Abdallah

et al. 2019

Journal of Heterocyclic Chem

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Treatment of N-phenyl-substituted benzenecarbo-hydrazonoyl chlorides 1ad with malononitrile in sodium ethoxide solution gave 5-amino-4-cyanopyrazole derivatives 2-5. Compounds 2-5 were converted to formidate derivatives 6-9 upon treatment with TEOF in acetic anhydride. The reaction of the latter products 6-9 with hydrazine hydrate gave imino-amino derivatives 10-13, which was converted to hydrazino derivatives 14-17 by refluxing with hydrazine hydrate. Hydrazino as well as imino-amino derivatives undergo condensation, cyclization, and cycloaddition reactions to give pyrazolo[3,4-d]pyrimidine 18-21, pyrazolo[4,3-e][1,2,4]triazolo-[3,4-c]pyrimidine 22-27, and pyrazolo[3 0 ,4 0 :4,5]pyrimido[1,6-b][1,2,4]triazine 42-44 derivatives. Antimicrobial studies are performed using two Gram-positive bacteria and two Gram-negative bacteria. Data indicated that compounds 5, 28D, 29B, and 31D are exploring elevated antibacterial effects against all strains tested. Compound 28D is the most promising antibacterial agent against the delicate bacterial strain Bacillus subtilis and Pseudomonas aeruginosa with high effectiveness (low minimum inhibitory concentration [MIC] value) 40 and 60 μg/mL, respectively.

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Two approaches to a new heterocyclic system of pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidine

Cited by 4 publications

References 8 publications

Synthesis and antitumor evaluation of some new derivatives and fused heterocyclic compounds derived from thieno[2,3‐b]pyridine: Part 2

Synthesis and antitumor evaluation of some new derivatives and fused heterocyclic compounds derived from thieno[2,3‐b]pyridine: Part 2

A Convenient Route for the Synthesis of Novel 2-Substituted [1,2,4]Triazolo[1,5-c]pyrimidine Derivatives

Synthesis, reactions, and antimicrobial activity of some novel pyrazolo[3,4‐d]pyrimidine, pyrazolo[4,3‐e][1,2,4]triazolo[1,5‐c]pyrimidine, and pyrazolo[4,3‐e][1,2,4]triazolo[3,4‐c]pyrimidine derivatives

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