Recent developments in aminopyrazole chemistry

Anwar, Hany F.; Elnagdi, Mohamed Hilmy

doi:10.3998/ark.5550190.0010.107

Cited by 98 publications

(22 citation statements)

References 18 publications

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“…[41] The reaction mechanism was assumed to occur via two alternative routes; new heterocycles could be obtained by an initially adding of an exocyclic amino group to the activated double bond in arylidene malononitrile through Michael addition. Then, the cyclization has occurred via the addition of endocyclic NH to the cyano function or the reverse route followed by autoxidation to afford either the 4-aminopyrazolo[1,5-a]pyrimidine derivatives [42,43] or its isomer 2-aminopyrazolo[1,5-a]pyrimidine [43][44][45] , respectively. Spectroscopic data could not distinguish between two possible isomers [46] .…”

Section: Resultsmentioning

confidence: 99%

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

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 IC50 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 IC50 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

Hassan

Sarg

El‐Sebaey

2019

Journal of Heterocyclic Chem

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“…The 3(5)-aminopyrazoles are currently used as starting materials in many important chemical reactions. Their use spans from the synthesis of different types of compounds with applications in pharmaceutics and agrochemical industries to the development of functional materials [ 5 , 6 , 7 , 8 ]. In spite of their widespread practical interest, these compounds have only been scarcely studied from the structural point of view at the molecular level, and the available information about their vibrational properties and photochemistry is also lacking.…”

Section: Introductionmentioning

confidence: 99%

Structure and IR Spectra of 3(5)-Aminopyrazoles and UV-Induced Tautomerization in Argon Matrix

et al. 2021

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The prototropic tautomerism in 3(5)-aminopyrazoles was investigated by matrix isolation infrared (IR) spectroscopy, supported by DFT(B3LYP)/6-311++G(d,p) calculations. In consonance with the experimental data, the calculations predict tautomer 3-aminopyrazole (3AP) to be more stable than the 5-aminopyrazole (5AP) tautomer (calculated energy difference: 10.7 kJ mol−1; Gibbs free energy difference: 9.8 kJ mol−1). The obtained matrix isolation IR spectra (in both argon and xenon matrices) were interpreted, and the observed bands were assigned to the tautomeric forms with help of vibrational calculations carried out at both harmonic and anharmonic levels. The matrix-isolated compound (in argon matrix) was then subjected to in situ broadband UV irradiation (λ > 235 nm), and the UV-induced transformations were followed by IR spectroscopy. Phototautomerization of the 3AP tautomer into the 5AP form was observed as the strongly prevalent reaction.

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“…Pyrazol‐5‐amines are well‐known for possessing a variety of biological activities and used in pharmacological chemistry [1–3] . For example, antimicrobial and antineoplastic activities, [4] anti‐inflammatory muscle relaxants, [5,6] potent aurora kinase inhibitors, [7] cyclin‐dependent kinase inhibitors, [8,9] potential BRAFV600E inhibitors, [10] and novel antitubulin agents [11] .…”

Section: Introductionmentioning

confidence: 99%

Pd‐Catalyzed N‐Arylations of 3‐Aryl‐1‐tosyl‐1H‐pyrazol‐5‐amines with Arylbromides and the Migration of Ts Group

Yang

et al. 2021

ChemCatChem

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An efficient palladium‐catalyzed N‐arylations of 3‐aryl‐1‐tosyl‐1H‐pyrazol‐5‐amines with arylbromides is established. A series of diversified N‐arylated products are obtained in excellent yields with broad substrate scope. Importantly, the N‐arylated products undergo 1,4‐ and 1,6‐migration reactions of Ts group under the action of Cs2CO3, affording the N‐Ts‐substituted pyrroles as major products (1,6‐migration). Similar results can also be directly obtained by palladium‐catalyzed reactions of 3‐aryl‐1‐tosyl‐1H‐pyrazol‐5‐amines with arylbromides in the presence of Cs2CO3 as a base. Mechanistic studies reveal that the Ts‐migration is achieved through an intermolecular pathway.

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Recent developments in aminopyrazole chemistry

Cited by 98 publications

References 18 publications

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

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

Structure and IR Spectra of 3(5)-Aminopyrazoles and UV-Induced Tautomerization in Argon Matrix

Pd‐Catalyzed N‐Arylations of 3‐Aryl‐1‐tosyl‐1H‐pyrazol‐5‐amines with Arylbromides and the Migration of Ts Group

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