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Someswara Rao Kosuru, Ting-Han Sun, Li-Fang Wang, Jaya Kishore Vandavasi, Wei-Yi Lu, Yi-Chun Lai, Sodio C N Hsu, Michael Y Chiang, Hsuan-Ying Chen
A series of dinuclear aluminum (Al2Pyr2) complexes bridged by two pyrazole ligands were synthesized, and their catalytic activity toward ring-opening polymerization of ε-caprolactone (CL) was investigated. Different types of the Al-N-N-Al-N-N skeletal ring were found among these Al2Pyr2 complexes. The butterfly form, L(Thio)2Al2Me4, exerted the highest catalytic activity for CL polymerization. κ(2)-CL coordination with both Al centers within the butterfly form L(Thio)2Al2Me4 facilitates the initiation process...
June 27, 2017: Inorganic Chemistry
Huapeng Liu, Xiao Cheng, Houyu Zhang, Yue Wang, Hongyu Zhang, Shigehiro Yamaguchi
Structurally simple pyrazole derivatives that exhibit excited-state intramolecular proton transfer (ESIPT) were synthesized. While these compounds displayed deep violet fluorescence in solution, in the crystalline state they showed white emission from the enol and keto forms.
June 27, 2017: Chemical Communications: Chem Comm
Guijie Li, Alicia Wolfe, Jason Brooks, Zhi-Qiang Zhu, Jian Li
The design, synthesis, and characterization of a series of tetradentate cyclometalated Pt(II) complexes are reported. The platinum complexes have the general structure Pt(ppz-O-CbPy-R), where a tetradentate cyclometalating ligand is consisting of ppz (3,5-dimethyl-1-phenyl-pyrazole), CbPy (carbazolylpyridine) components, and an oxygen bridging group. Variations of the R group on the pyridyl ring with various electron withdrawing and donating substituents are shown to have profound effects on the photophysical properties of Pt complexes...
June 26, 2017: Inorganic Chemistry
Malledevarapura Gurumurthy Prabhudeva, Srinivasan Bharath, Achutha Dileep Kumar, Shivalingegowda Naveen, Neratur Krishnappagowda Lokanath, Bantaganahalli Ningappa Mylarappa, Kariyappa Ajay Kumar
Oxidative-stress induces inflammatory diseases and infections caused by drug-resistant microbial strains are on the rise necessitating the discovery of novel small-molecules for intervention therapy. The current study presents an effective and new green protocol for the synthesis of thiophene-appended pyrazoles through 3+2 annulations method. Chalcones 3(a-g) were prepared from 5-chloro-2-acetylthiophene and aromatic aldehydes by Claisen-Schmidt approach. The reaction of chalcones 3(a-g) with phenylhydrazine hydrochlorides 4(a-b) in acetic acid (30%) medium and also with freshly prepared citrus extract medium under reflux conditions produced the thiophene appended pyrazoles 5(a-l) in moderate yields...
June 16, 2017: Bioorganic Chemistry
Yongliang Tu, Zhenming Zhang, Tao Wang, Jiamei Ke, Junfeng Zhao
A palladium-catalyzed oxidative carbonylation of arylhydrazines and alkynes with balloon pressure CO/O2 to afford trisubstituted pyrazoles in a one-pot manner has been developed. The formation of trisubstituted pyrazoles involves a sequential C-N bond cleavage, carbonylation, Sonogashira coupling, Michael addition, and intramolecular condensation cyclization tandem process. An unprecedented oxidative Sonogashira-carbonylation reaction of arylhydrazine plays a key role for such a facile approach to pyrazoles...
June 22, 2017: Organic Letters
Guangrong Meng, Roman Szostak, Michal Szostak
The formation of C-C bonds from amides by catalytic activation of the amide bond has been thus far possible by steric distortion. Herein, we report the first example of a general Pd-catalyzed Suzuki-Miyaura cross-coupling of planar amides enabled by the combination of (i) electronic-activation of the amide nitrogen in N-acylpyrroles and pyrazoles and (ii) the use of a versatile Pd-NHC catalysis platform. The origin and selectivity of forming acylmetals, including the role of twist, are discussed.
June 22, 2017: Organic Letters
Yegor Yartsev, Vitaliy Palchikov, Alexandr Gaponov, Svitlana Shishkina
The title compound, C15H13ClN4, crystallizes with two independent mol-ecules (A and B) in the asymmetric unit, which are far from planar as a result of steric repulsion between the rings. The benzene and phenyl rings are inclined to the central pyrazole ring by 46.64 (10) and 17.87 (10)° in mol-ecule A, and by 40.02 (10) and 14.18 (10)° in mol-ecule B. The aromatic rings are inclined to one another by 58.77 (9)° in mol-ecule A, and 36.95 (8)° in mol-ecule B. In the crystal, the A and B mol-ecules are linked by two pairs of N-H⋯N hydrogen bonds forming A-B dimers...
June 1, 2017: Acta Crystallographica. Section E, Crystallographic Communications
Ewa Szymańska, Paulina Chałupnik, Tommy N Johansen, Birgitte Nielsen, Ana Maria Cuñado Moral, Darryl S Pickering, Anna Więckowska, Katarzyna Kieć-Kononowicz
A series of racemic unnatural amino acids was rationally designed on the basis of recently published X-ray structures of the GluA2 LBD with bound phenylalanine-based antagonists. Twelve new diaryl- or aryl/heteroaryl-substituted phenylalanine derivatives were synthesized and evaluated in vitro in radioligand binding assays at native rat ionotropic glutamate receptors. The most interesting compound in this series, (RS)-2-amino-3-(3'-hydroxy-5-(1H-pyrazol-4-yl)-[1,1'-biphenyl]-3-yl)propanoic acid 7e, showed the binding affinity of 4...
June 21, 2017: Chemical Biology & Drug Design
Joseph Carpenter, Ying Wang, Gang Wu, Jianxin Feng, Xiang-Yang Ye, Christian L Morales, Matthias Broekema, Karen A Rossi, Keith J Miller, Brian J Murphy, Ginger Yingzhe Wu, Sarah E Malmstrom, Anthony V Azzara, Philip M Sher, John M Fevig, Andrew Alt, Robert L Bertekap, Mary Jane Cullen, Timothy M Harper, Kimberly A Foster, Chiuwa Emily Luk, Qian Xiang, Mary F Grubb, Jeffrey A Robl, Dean A Wacker
Agonism of the 5-HT2C receptor represents one of the most well-studied and clinically-proven mechanisms for pharmacological weight reduction. Selectivity over the closely related 5-HT2A and 5-HT2B receptors is critical as their activation has been shown to lead to undesirable side-effects and major safety concerns. In this communication, we report the development of a new screening paradigm which utilizes an active site mutant D134A 5-HT2C receptor to identify atypical agonist structures. We additionally report the discovery and optimization of a novel class of non-basic heterocyclic amide agonists of 5-HT2C...
June 21, 2017: Journal of Medicinal Chemistry
Vasiliy M Muzalevskiy, Alexander Yu Rulev, Alexey R Romanov, Evgeniy V Kondrashov, Igor A Ushakov, Vyacheslav A Chertkov, Valentine Georgievich Nenajdenko
A detailed study of the reaction of trifluoroacetylated acetylenes and aryl(alkyl) hydrazines was performed aimed to the regioselective synthesis of 3- or 5-trifluoromethylated pyrazoles. It was found that the regioselectivity of reaction depends dramatically on the solvent nature. Highly polar protic solvents (hexafluoroisopropanol) favor the formation of 3-trifluoromethylpyrazoles. In contrast, when the reaction was performed in polar aprotic solvents (DMSO), the formation of their 5-CF3-substituted isomers was preferentially observed...
June 18, 2017: Journal of Organic Chemistry
Nádia Ribeiro, Somnath Roy, Nataliya Butenko, Isabel Cavaco, Teresa Pinheiro, Irina Alho, Fernanda Marques, Fernando Avecilla, João Costa Pessoa, Isabel Correia
Since the discovery of cisplatin there has been a continuous pursuit for new metallodrugs showing higher efficacies and lower side effects. In this work, new copper(II) complexes (C1-C6) of Schiff bases derived from pyrazolyl were developed. Through condensation of 5-methyl-1H-pyrazole-3-carbohydrazide with different aromatic aldehydes - pyridoxal, salicylaldehyde, 3-methoxy-2-hydroxybenzaldehyde, 3-ethoxy-2-hydroxybenzaldehyde and 2-hydroxynaphthene-1-carbaldehyde - a set of new pyrazole based "ONO" tridentate Schiff bases were obtained in moderate to good yields - L1-L6, as well as their Cu(II)-complexes...
June 1, 2017: Journal of Inorganic Biochemistry
Mahmood Ahmed, Muhammad Abdul Qadir, Abdul Hameed, Muhammad Nadeem Arshad, Abdullah M Asiri, Muhammad Muddassar
Curcumin has shown large number of pharmacological properties against different phenotypes of various disease models. Different synthetic routes have been employed to develop its various derivatives for diverse biological functions. In this study, curcumin derived azomethine, isoxazole, pyrimidines and N-substituted pyrazoles were synthesized to investigate their urease enzyme inhibition. The structures of newly synthesized compounds were described by IR, MS, (1)H NMR and (13)C NMR spectral data. Urease enzyme inhibition was evaluated through in vitro assays in which compound 8b was found to be the most potent (IC50 = 2...
June 13, 2017: Biochemical and Biophysical Research Communications
Lalit Khillare, Manisha Bhosle, Mahendra Bhalerao, Kiran Kharat, Ramrao Mane
BACKGROUND: 2, 4-Thiazolidinedione (TZD), pyrazole and thiazole heterocyclic rings exhibit wide range of pharmacological activities. Medicinal chemists use these heterocyclic moieties as scaffolds in drug designing and discovery. The existing medicaments, celecoxib and meloxicam, used for treating inflammation and pain are having, pyrazole and thiazole, respectively as a key scaffolds. Pyrazoles coupled with 2, 4-thiazolidinediones may display enhanced anti inflammatory activity. With this hope the title work was carried...
June 16, 2017: Anti-inflammatory & Anti-allergy Agents in Medicinal Chemistry
Ting-Ting Yao, Dou-Xin Xiao, Zhong-Shan Li, Jing-Li Cheng, Shao-Wei Fang, Yong-Jun Du, Jin-Hao Zhao, Xiao-Wu Dong, Guo-Nian Zhu
The identification of novel succinate dehydrogenase (SDH) inhibitors represents one of the most attractive directions in the field of fungicide research and development. During our continuous efforts to pursue inhibitors belonging to this class, some structurally novel pyrazole-furan carboxamide and pyrazole-pyrrole carboxamide derivatives have been discovered via the introduction of scaffold hopping and bioisosterism to compound 1, a remarkably potent lead obtained by pharmacophore-based virtual screening...
June 26, 2017: Journal of Agricultural and Food Chemistry
Rossana Galassi, Mukunda M Ghimire, Brooke M Otten, Simone Ricci, Roy N McDougald, Ruaa M Almotawa, Dieaa Alhmoud, Joshua F Ivy, Abdel-Monem M Rawashdeh, Vladimir N Nesterov, Eric W Reinheimer, Lee M Daniels, Alfredo Burini, Mohammad A Omary
Outer-shell s(0)/p(0) orbital mixing with d(10) orbitals and symmetry reduction upon cupriphication of cyclic trinuclear trigonal-planar gold(I) complexes are found to sensitize ground-state Cu(I)-Au(I) covalent bonds and near-unity phosphorescence quantum yields. Heterobimetallic Au4Cu2 {[Au4(μ-C(2),N(3)-EtIm)4Cu2(µ-3,5-(CF3)2Pz)2], (4a)}, Au2Cu {[Au2(μ-C(2),N(3)-BzIm)2Cu(µ-3,5-(CF3)2Pz)], (1) and [Au2(μ-C(2),N(3)-MeIm)2Cu(µ-3,5-(CF3)2Pz)], (3a)}, AuCu2 {[Au(μ-C(2),N(3)-MeIm)Cu2(µ-3,5-(CF3)2Pz)2], (3b) and [Au(μ-C(2),N(3)-EtIm)Cu2(µ-3,5-(CF3)2Pz)2], (4b)} and stacked Au3/Cu3 {[Au(μ-C(2),N(3)-BzIm)]3[Cu(µ-3,5-(CF3)2Pz)]3, (2)} form upon reacting Au3 {[Au(μ-C(2),N(3)-(N-R)Im)]3 ((N-R)Im = imidazolate; R = benzyl/methyl/ethyl = BzIm/MeIm/EtIm)} with Cu3 {[Cu(μ-3,5-(CF3)2Pz)]3 (3,5-(CF3)2Pz = 3,5-bis(trifluoromethyl)pyrazolate)}...
June 14, 2017: Proceedings of the National Academy of Sciences of the United States of America
T P Lehmann, J Kujawski, J Kruk, K Czaja, M K Bernard, P P Jagodzinski
Pyrazoles and their derivatives belong to a class of compounds that demonstrate a great potential in design of anticancer, antiangiogenic, and antimetastatic drugs. Our earlier studies showed that pyrazole derivatives TOSPYRQUIN and TOSIND diminished viability of colorectal adenocarcinoma cells HT-29. Here we demonstrated for the first time in human mammary gland adenocarcinoma cell lines MCF7 and MDA-MB-231 cells the cytotoxic effects of four pyrazole derivatives: TOSIND, PYRIND, METPYRIND, and DIPYR. Three pyrazoles: PYRIND, METPYRIND, and one novel unpublished derivative DIPYR were tested for the first time in living cells...
April 2017: Journal of Physiology and Pharmacology: An Official Journal of the Polish Physiological Society
Chang-Sheng Wang, Xiao-Feng Wu, Pierre H Dixneuf, Jean-Francois Soule
A copper-catalyzed oxidative C(sp3)-H/N-H coupling of NH-heterocycles with affordable (cyclo)alkanes was developed. This protocol involved C(sp3)-N bond formation via a radical pathway generated by a homolytic cleavage of di-tert-butyl peroxide and trapping of the radical(s) by copper catalysts. The reaction tolerated a series of functional groups, such as bromo, fluoro, ester, ketone, nitrile, methyl and methoxy. NH-free indoles, pyroles, pyrazoles, indazoles and benzotriazoles have been successfully N-alkylated...
June 14, 2017: ChemSusChem
Anna Kusakiewicz-Dawid, Monika Porada, Wioletta Ochędzan-Siodłak, Małgorzata A Broda, Maciej Bujak, Dawid Siodłak
A series of model compounds containing 3-amino-1H-pyrazole-5-carboxylic acid residue with N-terminal amide/urethane and C-terminal amide/hydrazide/ester groups were investigated by using NMR, Fourier transform infrared, and single-crystal X-ray diffraction methods, additionally supported by theoretical calculations. The studies demonstrate that the most preferred is the extended conformation with torsion angles ϕ and ψ close to ±180°. The studied 1H-pyrazole with N-terminal amide/urethane and C-terminal amide/hydrazide groups solely adopts this energetically favored conformation confirming rigidity of that structural motif...
June 13, 2017: Journal of Peptide Science: An Official Publication of the European Peptide Society
Y Avraham, I Paturski, I Magen, L Vorobiev, E M Berry
We have investigated the effects of 0.001mg/kg 2-arachidonoylglycerol (2-AG) administered in combination with compounds present in the body alongside 2-AG like 2-palmitoylglycerol and 2-linoleylglycerol (also termed "entourage"), on cognitive function,food intake, and neurotransmitter levels in the hippocampus and hypothalamus of mice under diet restriction. Young female Sabra mice were treated with vehicle, 2-AG, 2-AG + entourage, 2-AG + entourage + 5-(4-Chlorophenyl)-1-(2,4-dichloro-phenyl)- 4-methyl-N-(piperidin-1-yl)-1H-pyrazole-3-carboxamide (SR141716A, a CB1 antagonist) and SR141716A...
June 9, 2017: Brain Research
Dalia R Emam, Ahmad M Alhajoj, Khaled M Elattar, Nabila A Kheder, Ahmed A Fadda
Diazocoupling reaction of curcumin with different diazonium salts of p-toluidine, 2-aminopyridine, and 4-aminoantipyrine in pyridine yielded the arylhydrazones 2a-c. Arylhydrazone of p-toluidine reacted with urea, thiourea, and guanidine nitrate to produce 5,6-dihydropyrimidines. Further reaction of 2a with 2,3-diaminopyrdine in sodium ethoxide solution yielded 1H-pyrido[2,3-b][1,4]diazepine derivative. Bis(2,5-dihydroisoxazole) is obtained from the reaction of 2a with hydroxylamine hydrochloride, while its reactions with hydrazines afforded the respective 4,5-dihydro-1H-pyrazoles...
June 11, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
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