Showing papers on "Pyrazole published in 2013"
TL;DR: The results revealed that the compound 11c having 2,5-dichlorothiophene substituent on pyrazole moiety and a triazole ring showed significant analgesic and antimicrobial activity.
246 citations
TL;DR: In this article, a series of strongly greenish-blue to blue emitting Cu(NN)(POP)+ (POP = bis[2-(dipenylphosphino)phenyl]ether) complexes containing N-linked 2-pyridyl pyrazolate diimine ligands was designed and synthesized.
Abstract: A new series of strongly greenish-blue to blue emitting Cu(NN)(POP)+ (POP = bis[2-(dipenylphosphino)phenyl]ether) complexes containing N-linked 2-pyridyl pyrazolate diimine ligands [Cu(pypz)(POP)]BF4 (1), [Cu(pympz)(POP)]BF4 (2), and [Cu(pytfmpz)(POP)]BF4 (3) (pypz = 1-(2-pyridyl)pyrazole, pympz = 3-methyl-1-(2-pyridyl)pyrazole, and pytfmpz = 3-trifluoromethyl-1-(2-pyridyl)pyrazole) have been designed and synthesized. Their structural, electrochemical, and photophysical properties have been characterized. The complexes 1–3 exhibit high photoluminescence quantum yields (PLQYs) at room temperature both in nitrogen-saturated CH2Cl2 (up to 45%) and in neat solid (up to 87%), which are comparable to the reported highest values for the cuprous complexes. The temperature dependence of spectroscopic properties and emission decay behaviors reveal the presence of two thermally equilibrated emitting states. At temperatures below 150 K, the lowest triplet state (T1) is the predominant emitting state resulting in the ...
235 citations
TL;DR: Results confirm that novel pyrazolyl acyl thioureas derived compounds may be utilized for cancer treatment and have a great potential and significance for further investigations.
164 citations
TL;DR: The use of molecular modeling is reviewed in the designing of novel pyrazole analogs that may target various receptors such as protein kinase inhibitor, tyrosine kinases, Aurora-A kinase, tumor growth factor, cyclin dependent kinase (CDK) and fibroblast growth factor (FGF), which are significant for the management of cancer.
145 citations
TL;DR: In this article, Meglumine, a bio-based chemical, was demonstrated to be a highly efficient and reusable catalyst for the synthesis of a series of pyranopyrazole derivatives via a one-pot, four-component reaction of carbonyl compound or isatin, hydrazine hydrate, malononitrile, and β-keto ester in EtOH-H2O.
140 citations
TL;DR: A series of 2-pyrazolines 5–9 have been synthesized from α,β-unsaturated ketones 2–4 bearing benzenesulfonamide moieties and all the newly synthesized compounds have been characterized on the basis of IR and 1H-NMR spectral data as well as physical data.
Abstract: A series of 2-pyrazolines 5-9 have been synthesized from α,β-unsaturated ketones 2-4. New 2-pyrazoline derivatives 13-15 bearing benzenesulfonamide moieties were then synthesized by condensing the appropriate chalcones 2-4 with 4-hydrazinyl benzenesulfonamide hydrochloride. Ethyl [1,2,4] triazolo[3,4-c][1,2,4]triazino[5,6-b]-5H-indole-5-ethanoate (26) and 1-(5H-[1,2,4]triazino[5,6-b] indol-3-yl)-3-methyl-1H-pyrazol-5(4H)-one (32) were synthesized from 3-hydrazinyl-5H-[1,2,4]triazino[5,6-b]indole (24). On the other hand ethyl[1,2,4]triazolo[3,4-c][1,2,4]triazino[5,6-b]-5,10-dihydroquinoxaline- 5-ethanoate (27) and 1-(5,10-dihydro-[1,2,4]triazino[5,6-b]quinoxalin-3-yl)-3-methyl-1H-pyrazol-5(4H)-one (33) were synthesized from 3-hydrazinyl-5,10-dihydro-[1,2,4]triazino[5,6-b]quinoxaline (25) by reaction with diethyl malonate or ethyl acetoacetate, respectively. Condensation of 6,6-dimethyl-4-oxo-4,5,6,7-tetrahydro-1H-indole-2-carbaldehyde (1') with compound 24 or 25 afforded the corresponding Schiff's bases 36 and 37, respectively. Reaction of the Schiff's base 37 with benzoyl hydrazine or acetic anhydride afforded benzohydrazide derivative 39 and the cyclized compound 40, respectively. Furthermore, the pyrazole derivatives 42-44 were synthesized by cyclization of hydrazine derivative 25 with the prepared chalcones 2-4. All the newly synthesized compounds have been characterized on the basis of IR and 1H-NMR spectral data as well as physical data. Antimicrobial activity against the organisms E. coli ATCC8739 and P. aeruginosa ATCC 9027 as examples of Gram-negative bacteria, S. aureus ATCC 6583P as an example of Gram-positive bacteria and C. albicans ATCC 2091 as an example of a yeast-like fungus have been studied using the Nutrient Agar (NA) and Sabouraud Dextrose Agar (SDA) diffusion methods. The best performance was found for the compounds 16, 17, 19 and 20.
117 citations
TL;DR: It is found that a metal-ligand-bifunctional complex of iron with a pincer-type ligand bearing two proton-responsive pyrazole arms catalyzes the disproportionation of hydrazine into ammonia and dinitrogen.
Abstract: N–N bond cleavage of hydrazines on transition metals is of considerable importance in understanding the mechanism of biological nitrogen fixation under ambient conditions. We found that a metal–ligand-bifunctional complex of iron with a pincer-type ligand bearing two proton-responsive pyrazole arms catalyzes the disproportionation of hydrazine into ammonia and dinitrogen. The NH groups in the pyrazole ligands and hydrazines are crucial for the reaction, which most likely occurs through multiple and bidirectional proton-coupled electron transfer between the iron complex and hydrazine. The multiproton-responsive pincer-type ligand also stabilizes the intermediate diazene complex through a hydrogen-bonding network, as revealed by structural characterization of a κ1N-phenylhydrazine complex.
112 citations
TL;DR: The Ru(II)-catalyzed ortho-C-H amination directed by a weakly coordinating amide auxiliary with O-benzoyl hydroxylamines at room temperature has been achieved.
110 citations
TL;DR: A method for aliphatic C-H bond oxidation of oximes and hydrazones mediated by 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO) has been developed, which enables the concise assembly of substituted isoxazole and pyrazole skeletons.
105 citations
TL;DR: These NIR-luminescent complexes have potential application in optical communication, telecommunications, and fluoroimmunoassays and are good sensitizers for all the visible and NIR emitters effectively.
Abstract: A series of highly volatile eight-coordinate air and moisture stable lanthanide complexes of the type [Ln(hfaa)3(L)2] (Ln = Pr (1), Nd (2), Eu (3), Gd (4), Tb (5), Dy (6), Ho (7), Er (8), Tm (9), and Yb (10); hfaa = anion of hexafluoroacetylacetone and L = pyrazole) have been synthesized and characterized by elemental analysis, IR, ESI-MS+, and NMR studies. Single-crystal X-ray structures have been determined for the Eu(III) and Dy(III) complexes. These complexes crystallize in the monoclinic space group P21/c. The lanthanide ion in each of these complexes is eight-coordinate with six oxygen atoms from three hfaa and two N-atoms from two pyrazole units, forming a coordination polyhedron best describable as a distorted square antiprism. The NMR spectra reveal that both the pyrazole units remain attached to the metal in solution and the β-diketonate and pyrazole protons are shifted in opposite directions in the case of paramagnetic complexes. The lanthanide-induced chemical shifts are dipolar in nature. The...
102 citations
TL;DR: N-(4-(Pyrazol-4-yl)thiazol-2-yl)-N'-phenylthiourea derivative 2 was synthesized and then treated with variety of hydrazonoyl chlorides under basic condition at reflux to afford the corresponding 2-( 4-(pyrazol)-1,3,4-thiadiazole derivatives 6, 10a-e and 17a- e.
TL;DR: In silico molecular docking study results showed that, all the synthesized compounds having minimum binding energy and have good affinity toward the active pocket, thus, they may be considered as good inhibitor of GlcN-6-P synthase.
TL;DR: A practical Pd(II)/Phen catalyst and conditions for direct C-3 arylation of indazole and pyrazole with ArI or ArBr without using Ag additives as halide scavengers are reported.
Abstract: C3-arylated indazole and pyrazoles are privileged structural motifs in agrochemicals and pharmaceuticals. C-3 C–H arylation of (1H) indazole and pyrazole has been a significant challenge due to the poor reactivity of the C-3 position. Herein, we report a practical Pd(II)/Phen catalyst and conditions for the direct C-3 arylation of indazole and pyrazole with ArI or ArBr without using Ag additives as halide scavengers. The use of toluene, chlorobenzene, trifluoromethylbenzene and mesitylene as the solvent was found to be crucial for the selectivity and reactivity. We further demonstrate the robustness of this protocol through the first total synthesis of nigellidine hydrobromide as well as the expedient preparation of heterocycles structurally related to pesticides and drug molecules.
TL;DR: A novel Pd(OAc)2-NFSI-TFA system was developed for the highly selective ortho-monofluorination directed by diverse aryl-N-heterocyclic directing groups e.g., quinoxaline, pyrazole, benzo[d]oxazole, and pyrazine derivatives.
TL;DR: In this review, attempt has been made to disclose various therapeutic applications of pyrazine derivatives reported during the last decade.
Abstract: Pyrazine is one of the important class of heterocyclic compounds that can be obtained naturally or synthesized chemically. Pyrazine ring has got importance in exhibiting various biological activities in association with other scaffolds like pyrrole, pyrazole, imidazole, triazole, tetrazole, thiophene, oxazole, pyridine, piperidine and piperazine. Presence of pyrazine ring as a basic scaffold in various clinically used drugs exhibits its importance in drug design. In this review, attempt has been made to disclose various therapeutic applications of pyrazine derivatives reported during the last decade.
TL;DR: In this article, an efficient, green, and facile four-component reaction for the preparation of pyrano[2,3c]pyrazole derivatives through the condensation reaction of aryl aldehydes, ethyl acetoacetate, malononitrile, and hydrazine hydrate or phenyl hydride under aqueous condition is reported.
Abstract: Article history: Received March 20, 2013 Received in Revised form July 7, 2013 Accepted 10 July 2013 Available online 12 July 2013 An efficient, green, and facile four-component reaction for the preparation of pyrano[2,3c]pyrazole derivatives through the condensation reaction of aryl aldehydes, ethyl acetoacetate, malononitrile, and hydrazine hydrate or phenyl hydrazine in the presence of commercially available organocatalyst sodium benzoate under aqueous condition is reported. The products are produced with high yields and in shorter reaction times. It also is mild, safe, green and environmental friendly. © 2013 Growing Science Ltd. All rights reserved.
TL;DR: Aiming for the synthesis of new heterocyclic compounds containing a sulfonamido moiety suitable for use as antibacterial agents, the precursor ethyl {[4-N-(4,6-dimethylpyrimidin-2-yl)sulfamoyl]phenylazo}cyanoacetate was reacted with a variety of active methylene compounds producing pyran, pyridine and pyridazine derivatives.
Abstract: Aiming for the synthesis of new heterocyclic compounds containing a sulfonamido moiety suitable for use as antibacterial agents, the precursor ethyl {[4-N-(4,6-dimethylpyrimidin-2-yl)sulfamoyl]phenylazo}cyanoacetate was reacted with a variety of active methylene compounds producing pyran, pyridine and pyridazine derivatives. Also, the reactivity of the precursor hydrazone towards hydrazine derivatives to give pyrazole and oxazole derivatives was studied. On the other hand, treatment of the same precursor with urea, thiourea and/or guanidine hydrochloride furnished pyrimidine and thiazine derivatives, respectively. The newly synthesized compounds were tested for antibacterial activity, whereby eight compounds were found to have high activities.
TL;DR: In this article, the synthesis and characterization of N,N,O-chelate zinc enolate complexes and the catalysis of the complexes for the ROP of rac-lactide are reported.
TL;DR: Compounds 3f and 3c have exhibited significant biological activity against the tested microorganisms.
TL;DR: Two series of novel isosteviol-fused pyrazoline and pyrazole derivatives were facilely synthesized via intramolecular 1,3-dipolar cycloaddition and condensation reaction, respectively and exhibited noteworthy cytotoxic activities.
TL;DR: New pyrazole derivatives were designed and synthesized as potential protein kinase inhibitors in the view to develop specific antitumor therapies and one 3-aminopyrazole derivative emerged as a potential candidate for the development of future cytotoxic compounds.
Abstract: New pyrazole derivatives were designed and synthesized as potential protein kinase inhibitors in the view to develop specific antitumor therapies. The structures of the compounds were elucidated using spectral and elemental analyses. The antitumor potential was estimated using wheat seeds and the general toxicity was evaluated by alternative methods, using invertebrate animals. One 3-aminopyrazole derivative emerged as a potential candidate for the development of future cytotoxic compounds.
TL;DR: It is found that curcumin also loses its activity instantaneously in a reducing environment, and results strongly suggest that compounds 2 and 3 could be good replacements forCurcumin in future drug development.
Abstract: Curcumin has shown promising therapeutic utilities for many diseases, including cancer; however, its clinical application is severely limited because of its poor stability under physiological conditions. Here we find that curcumin also loses its activity instantaneously in a reducing environment. Curcumin can exist in solution as a tautomeric mixture of keto and enol forms, and the enol form was found to be responsible for the rapid degradation of the compound. To increase the stability of curcumin, several analogues were synthesized in which the diketone moiety of curcumin was replaced by isoxazole (compound 2) and pyrazole (compound 3) groups. Isoxazole and pyrazole curcumins were found to be extremely stable at physiological pH, in addition to reducing atmosphere, and they can kill cancer cells under serum-depleted condition. Using molecular modeling, we found that both compounds 2 and 3 could dock to the same site of tubulin as the parent molecule, curcumin. Interestingly, compounds 2 and 3 also show better free radical scavenging activity than curcumin. Altogether, these results strongly suggest that compounds 2 and 3 could be good replacements for curcumin in future drug development.
TL;DR: It is sincerely hope that increasing knowledge of the SAR and cellular processes underlying the bioactivity of pyrazole derivatives will be beneficial to the rational design of new generation of small molecule drugs.
Abstract: Within the past years, many researches on the synthesis, structure-activity relationships (SAR), antitumor, antiinflammatory and anti-bacterial activities of the pyrazole derivatives have been reported. Several pyrazole derivatives possess important pharmacological activities and they have been proved useful materials in drug research. Pyrazole derivatives play an important role in antitumor agents because of their good inhibitory activity against BRAF(V600E), EGFR, telomerase, ROS Receptor Tyrosine Kinase and Aurora-A kinase. In addition, pyrazole derivatives also show good antiinflammatory and anti-bacterial activities. In this review, the bioactivities of the pyrazole derivatives mentioned above will be summarized in detail. We sincerely hope that increasing knowledge of the SAR and cellular processes underlying the bioactivity of pyrazole derivatives will be beneficial to the rational design of new generation of small molecule drugs.
TL;DR: It is proposed that VdW's radii of the substitution (bulkiness) in ring B determine the potency of phenyl carbamates.
TL;DR: A new series of fluoro substituted pyrazoline derivatives 5 a-g and 6a-g were synthesized in good to excellent yield from the corresponding pyrazole chalcones by using polyethylene glycol-400 (PEG-400) as an alternative reaction medium.
TL;DR: One pot solvent-free synthetic method is developed for the synthesis of novel pyrano[2,3-c]pyrazole analogs, which are selectively toxic against cancer cells and not normal cells.
Abstract: One pot solvent-free synthetic method is developed for the synthesis of novel pyrano[2,3-c]pyrazole analogs. Cytotoxicity experiments conducted against a pair of cancerous, non-cancerous lung cell lines, and a cervical cell line is described. These compounds are selectively toxic against cancer cells and not normal cells. Molecular mechanism is established for the mode of DNA binding of these compounds using electrochemical and proton NMR methods.
TL;DR: In this paper, the structures of 243 pyrazoles with their corresponding biological activities are reported and all of them are represented around the common structure of the pyrazole ring even in those cases where the heterocycle is only a minor part of the molecule.
Abstract: In this review, we report the structures of 243 pyrazoles with their corresponding biological activities. All of them are represented around the common structure of the pyrazole ring even in those cases where the heterocycle is only a minor part of the molecule. The classification we have used is based on chemical structure considerations and not in terms of the therapeutic area which is the more common approach. Some general conclusions have been drawn linking structures with activities.
TL;DR: A series of carbamate functionalized spiro compounds were synthesized by [3+2]-cycloaddition and condensation reactions based on methyl {4(3)-[2-(2-oxo-1,2-dihydro-3H-indol-3-ylidene)acetyl]phenyl} carbamates as mentioned in this paper.
Abstract: A series of carbamate-functionalized spiro compounds were synthesized by [3+2]-cycloaddition and condensation reactions based on methyl {4(3)-[2-(2-oxo-1,2-dihydro-3H-indol-3-ylidene)acetyl]phenyl}carbamates. The antimicrobial activity with respect to E. coli, S. aureus 209, and Micrococcus and antifungal activity with respect to Microsporum canis, Trichophyton rubrum, and Candida albicans were investigated. The most active of the synthesized compounds were spiro compounds with isoxazoline and pyrazole fragments.
TL;DR: 4-nitroacetophenone, on condensation with appropriate aldehydes in ethanolic sodium hydroxide solution, yielded the corresponding chalcones, which led to the formation of corresponding novel pyrazole, pyrimidine, and isooxazole derivatives, respectively.
Abstract: In the present investigation, 4-nitroacetophenone, on condensation with appropriate aldehydes in ethanolic sodium hydroxide solution, yielded the corresponding chalcones. These corresponding chalcones were reacted with hydrazine hydrate, urea, thiourea, and hydroxylamine hydrochloride, which led to the formation of corresponding novel pyrazole, pyrimidine, and isooxazole derivatives, respectively. All newly synthesized compounds were evaluated for their antimycobacterial activities against Mycobacterium tuberculosis using agar dilution. The results indicated that most of the compounds demonstrated better in vitro antitubercular activity, and the compound 1g has a MIC of 1.56 μg mL−1. QSAR analysis revealed that molecular descriptors mean electrotopological state (Ms) and average valance connectivity index chi-0 (0χAv) contributed positively while 3-path Kier alpha-modified shape index (3κα) contributed negatively. The objective of our study is to generate new leads and to optimize their structure to display the potent efficacy.
TL;DR: Compound 10b, a series of 1,3-diphenyl-N-(phenylcarbamothioyl)-1H-pyrazole-4-carboxamide derivatives, inhibited CDK2 with an IC50 value of 25 nM, counteracting tumor cell proliferation of three cancer cell lines and indicated that compound 10b could induce cycle G0/G1 phase arrest in A549 cells with a dose dependent.