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https://www.readbyqxmd.com/read/29149081/-19-f-nmr-diastereotopic-signals-in-two-n-chf%C3%A2-derivatives-of-4s-7r-7-8-8-trimethyl-4-5-6-7-tetrahydro-4-7-methano-2h-indazole
#1
Diana García-Pérez, Concepción López, Rosa M Claramunt, Ibon Alkorta, José Elguero
In this paper, we report the anisochrony of the fluorine atoms of a CHF₂ group when linked to a pyrazole ring. The pyrazole is part of (4S,7R)-7,8,8-trimethyl-4,5,6,7-tetrahydro-4,7-methano-2H-indazole also known as (4S,7R)-campho[2,3-c]pyrazole, which has two stereogenic centers. Gauge-Independent Atomic Orbital (GIAO)/Becke, 3-parameter, Lee-Yang-Parr (B3LYP)/6-311++G(d,f) calculated (19)F chemical shifts of the minimum energy conformations satisfactorily agree with the experimental data. The energy differences between minima need to consider solvent effects (continuum model) to be satisfactorily reproduced...
November 17, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/29148763/discovery-of-n-3-carbamoyl-5-5-7-7-tetramethyl-5-7-dihydro-4h-thieno-2-3-c-pyran-2-yl-lh-pyrazole-5-carboxamide-glpg1837-a-novel-potentiator-which-can-open-class-iii-mutant-cystic-fibrosis-transmembrane-conductance-regulator-cftr-channels-to-a-high-extent
#2
Steven Emiel Van der Plas, Hans Kelgtermans, Tom De Munck, Sébastien Laurent Xavier Martina, Sébastien Dropsit, Evelyne Quinton, Ann De Blieck, Caroline Joannesse, Linda Tomaskovic, Mia Jans, Thierry Christophe, Ellen Van der Aar, Monica Borgonovi, Luc Nelles, Maarten Gees, Pieter Fw Stouten, Jan Van Der Schueren, Oscar Mammoliti, Katja Conrath, Martin J Andrews
Cystic fibrosis (CF) is caused by mutations in the gene for the cystic fibrosis transmembrane conductance regulator (CFTR). With the discovery of Ivacaftor and Orkambi, it has been shown that CFTR function can be partially restored by administering one or more small molecules. These molecules aim at either enhancing the amount of CFTR on the cell surface (correctors) or at improving the gating function of the CFTR channel (potentiators). Here we describe the discovery of a novel potentiator GLPG1837 which shows enhanced efficacy on CFTR mutants harboring Class III mutations compared to Ivacaftor, the first marketed potentiator...
November 17, 2017: Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/29144011/a-gold-catalyzed-domino-cyclization-enabling-rapid-construction-of-diverse-polyheterocyclic-frameworks
#3
Erik Van der Eycken, Yi He, Zhenghua Li, Koen Robeyns, Luc Van Meervelt
We report herein an efficient gold(I)-catalyzed post-Ugi domino dearomatization/ipso-cyclization/Michael sequence that enables access to libraries of diverse (hetero)arene-annulated tricyclic heterocycles. This process affords novel complex polycyclic scaffolds in moderate to good yields from readily available acyclic precursors with excellent chemo-, regio-, and diastereo-selectivity. The power of this strategy has been demonstrated by the rapid synthesis of 40 highly functionalized polyheterocycles bearing indole, pyrrole, (benzo)furan, (benzo)thiophene, pyrazole and electron-rich arenes in two-operational steps...
November 16, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/29143992/teaching-old-compounds-new-tricks-ddq-photocatalyzed-c-h-amination-of-arenes-with-carbamates-urea-and-n-heterocycles
#4
Somnath Das, Palani Natarajan, Burkhard König
The C-H amination of benzene derivatives was achieved using DDQ as photocatalyst and BocNH₂ as the amine source under aerobic conditions and visible light irradiation. Electron-deficient and electron-rich benzenes react as substrates with moderate to good product yields. The amine scope of the reaction comprises Boc-amine, carbamates, pyrazoles, sulfonimide and urea. Preliminary mechanistic investigations indicate a charge transfer complex between the amine and DDQ as essential intermediate of the reaction...
November 16, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/29143485/synthesis-molecular-modeling-and-biological-evaluation-of-4-5-aryl-3-thiophen-2-yl-4-5-dihydro-1h-pyrazol-1-yl-benzenesulfonamides-towards-acetylcholinesterase-carbonic-anhydrase-i-and-ii-enzymes
#5
Cem Yamali, Halise Inci Gul, Abdulilah Ece, Parham Taslimi, Ilhami Gulcin
In the present study, 4-[5-aryl-3-(thiophen-2-yl)-4,5-dihydro-1H-pyrazol-1-yl] benzenesulfonamides were synthesized and inhibition effects on AChE, hCA I and hCA II were evaluated. Ki values of the compounds towards hCA I were in the range of 24.2±4.6-49.8±12.8 nM while they were in the range of 37.3±9.0-65.3±16.7 nM towards hCA II. Ki values of the Acetazolamide were 282.1±19.7 nM and 103.60±27.6 nM towards both isoenzymes, respectively. The compounds inhibited AChE with Ki in the range of 22.7±10.3-109...
November 16, 2017: Chemical Biology & Drug Design
https://www.readbyqxmd.com/read/29140603/protic-nnn-and-ncn-pincer-type-ruthenium-complexes-featuring-trifluoromethyl-pyrazole-arms-synthesis-and-application-to-catalytic-hydrogen-evolution-from-formic-acid
#6
Yoshiko Nakahara, Tatsuro Toda, Asuka Matsunami, Yoshihito Kayaki, Shigeki Kuwata
The NNN and NCN pincer-type ruthenium(II) complexes featuring two protic pyrazol-3-yl arms with a trifluoromethyl (CF3) group at the 5-position were synthesized and structurally characterized to evaluate the impact of the substitution on the properties and catalysis. The Brønsted acidity increased by the highly electron-withdrawing CF3 pendants was demonstrated by the protonation-deprotonation experiments. By contrast, the infrared spectra of the carbonyl derivatives as well as the cyclic voltammogram indicated that the electron density of the ruthenium atom is little influenced by the CF3 group...
November 15, 2017: Chemistry, An Asian Journal
https://www.readbyqxmd.com/read/29138944/design-synthesis-conformational-and-molecular-docking-study-of-some-novel-acyl-hydrazone-based-molecular-hybrids-as-antimalarial-and-antimicrobial-agents
#7
Parvin Kumar, Kulbir Kadyan, Meenakshi Duhan, Jayant Sindhu, Vineeta Singh, Baljeet Singh Saharan
BACKGROUND: Acyl hydrazones are an important class of heterocyclic compounds promising pharmacological characteristics. Malaria is a life-threatening mosquito-borne blood disease caused by a plasmodium parasite. In some places, malaria can be treated and controlled with early diagnosis. However, some countries lack the resources to do this effectively. RESULTS: The present work involves the design and synthesis of some novel acyl hydrazone based molecular hybrids of 1,4-dihydropyridine and pyrazole (5a-g)...
November 14, 2017: Chemistry Central Journal
https://www.readbyqxmd.com/read/29137125/new-2-methoxy-acetylenic-acids-and-pyrazole-alkaloids-from-the-marine-sponge-cinachyrella-sp
#8
Amin Mokhlesi, Rudolf Hartmann, Tibor Kurtán, Horst Weber, Wenhan Lin, Chaidir Chaidir, Werner E G Müller, Georgios Daletos, Peter Proksch
Three new 2-methoxy acetylenic acids (1-3) and a known derivative (4), in addition to three new natural pyrazole alkaloids (5-7) were isolated from an Indonesian marine sponge of the genus Cinachyrella. Compounds 5 and 6 have previously been reported as synthetic compounds. The structures of the new compounds were established on the basis of one- and two-dimensional NMR spectroscopy as well as by mass spectrometric data. The absolute configuration of the new acetylenic acid derivatives (1-3) was established by ECD spectroscopy...
November 11, 2017: Marine Drugs
https://www.readbyqxmd.com/read/29132907/determination-of-3-5-dimethylpyrazolium-glyceroborate-nitrification-inhibitor-in-nitrogen-fertilizer-samples-hplc-dad-method-development-and-validation-for-3-5-dimethylpyrazole
#9
Serkan Şahan, Uğur Şahin, Mustafa Başaran, Oğuzhan Uzun, Adem Güneş
3,5 - Dimethylpyrazolium glyceroborate is a nitrification inhibitor (a member of pyrazole derivatives) used for the fixation of nitrogen into the soil. In this study, an HPLC-DAD method was developed and validated for determination of 3,5 - dimethylpyrazole in order to determine 3,5 - dimethylpyrazolium glyceroborate in fertilizer samples. For method development, analytical parameters like type of eluent solution and column filling material and device parameters like eluent flow rate, column oven temperature and measurement wavelength were all optimized...
November 2, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/29127936/synthesis-of-n-3-4-11-c-methylpiperazin-1-yl-1-5-methylpyridin-2-yl-1h-pyrazol-5-yl-pyrazolo-1-5-a-pyrimidine-3-carboxamide-as-a-new-potential-pet-agent-for-imaging-of-irak4-enzyme-in-neuroinflammation
#10
Xiaohong Wang, Wenzhi Xu, Caihong Miao, Fugui Dong, Wei Li, Min Wang, Mingzhang Gao, Qi-Huang Zheng, Zhidong Xu
The reference standard N-(3-(4-methylpiperazin-1-yl)-1-(5-methylpyridin-2-yl)-1H-pyrazol-5-yl)pyrazolo[1,5-a]pyrimidine-3-carboxamide (9) and its demethylated precursor N-(1-(5-methylpyridin-2-yl)-3-(piperazin-1-yl)-1H-pyrazol-5-yl)pyrazolo[1,5-α]pyrimidine-3-carboxamide (8) were synthesized from pyrazolo[1,5-a]pyrimidine-3-carboxylic acid and ethyl 2-cyanoacetate with overall chemical yield 13% in nine steps and 14% in eight steps, respectively. The target tracer N-(3-(4-[(11)C]methylpiperazin-1-yl)-1-(5-methylpyridin-2-yl)-1H-pyrazol-5-yl)pyrazolo[1,5-a]pyrimidine-3-carboxamide ([(11)C]9) was prepared from its precursor with [(11)C]CH3OTf through N-[(11)C]methylation and isolated by HPLC combined with SPE in 50-60% radiochemical yield, based on [(11)C]CO2 and decay corrected to EOB...
November 6, 2017: Applied Radiation and Isotopes
https://www.readbyqxmd.com/read/29125948/effects-of-cytotoxic-cis-and-trans-diammine-monochlorido-platinum-ii-complexes-on-selenium-dependent-redox-enzymes-and-dna
#11
Heidi Lemmerhirt, Steven Behnisch, Anja Bodtke, Christopher H Lillig, Lucia Pazderova, Jana Kasparkova, Viktor Brabec, Patrick J Bednarski
Here we present the preparation of 14 pairs of cis- and trans-diammine monochlorido platinum(II) complexes, coordinated to heterocycles (i.e., imidazole, 2-methylimidazole and pyrazole) and linked to various acylhydrazones, which were designed as potential inhibitors of the selenium-dependent enzymes glutathione peroxidase 1 (GPx-1) and thioredoxin reductase 1 (TrxR-1). However, no inhibition of bovine GPx-1 and only weak inhibition of murine TrxR-1 was observed in in vitro assays. Nonetheless, the cis configured diammine monochlorido Pt(II) complexes exhibited cytotoxic and apoptotic properties on various human cancer cell lines, whereas the trans configured complexes generally showed weaker potency with a few exceptions...
October 26, 2017: Journal of Inorganic Biochemistry
https://www.readbyqxmd.com/read/29120638/discovery-and-optimization-of-potent-cell-active-pyrazole-based-inhibitors-of-lactate-dehydrogenase-ldh
#12
Ganesha Rai, Kyle R Brimacombe, Bryan T Mott, Daniel J Urban, Xin Hu, Shyh-Ming Yang, Tobie D Lee, Dorian M Cheff, Jennifer Kouznetsova, Gloria A Benavides, Katie Pohida, Eric J Kuenstner, Diane K Luci, Christine M Lukacs, Douglas R Davies, David M Dranow, Hu Zhu, Gary Sulikowski, William J Moore, Gordon M Stott, Andrew J Flint, Matthew D Hall, Victor M Darley-Usmar, Leonard M Neckers, Chi V Dang, Alex G Waterson, Anton Simeonov, Ajit Jadhav, David J Maloney
We report the discovery and medicinal chemistry optimization of a novel series of pyrazole-based inhibitors of human lactate dehydrogenase (LDH). Utilization of a quantitative high-throughput screening paradigm facilitated hit identification, while structure-based design and multiparameter optimization enabled the development of compounds with potent enzymatic and cell-based inhibition of LDH enzymatic activity. Lead compounds such as 63 exhibit low nM inhibition of both LDHA and LDHB, submicromolar inhibition of lactate production, and inhibition of glycolysis in MiaPaCa2 pancreatic cancer and A673 sarcoma cells...
November 9, 2017: Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/29116786/discovery-of-a-potent-selective-t-type-calcium-channel-blocker-as-a-drug-candidate-for-the-treatment-of-generalized-epilepsies
#13
Olivier Bezençon, Bibia Heidmann, Romain Siegrist, Simon Stamm, Sylvia Richard, Davide Pozzi, Olivier Corminboeuf, Catherine Roch, Melanie Kessler, Eric A Ertel, Isabelle Reymond, Thomas Pfeifer, Ruben de Kanter, Michael Toeroek-Schafroth, Luca G Moccia, Jacques Mawet, Richard Moon, Markus Rey, Bruno Capeleto, Elvire Fournier
We report here the discovery and pharmacological characterization of N-(1-benzyl-1H-pyrazol-3-yl)-2-phenylacetamide derivatives as potent, selective, brain-penetrating T-type calcium channel blockers. Optimization focused mainly on solubility, brain penetration, and search for an aminopyrazole metabolite that would be negative in an Ames test. This resulted in the preparation and complete characterization of compound 66b (ACT-709478), which has been selected as clinical candidate.
November 8, 2017: Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/29115329/the-diaza-nazarov-cyclization-involving-a-2-3-diaza-pentadienyl-cation-for-the-synthesis-of-polysubstituted-pyrazoles
#14
Balakrishna Aegurla, Rama Krishna Peddinti
An unprecedented iodine-mediated diaza-Nazarov (DAN) type cyclization for the construction of substituted pyrazoles from easily available starting materials via an enamine-iminium ion intermediate is described. The oxidative cyclization worked under green conditions with remarkable regioselectivity. This one-pot, efficient and operationally simple three-component intramolecular regioselective DAN cyclization displayed a wide range of substrate scope. The dichotomy of reaction pathways has been explored with density functional theory in the gas phase and solution phase...
November 8, 2017: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/29113746/quinoline-derivatives-bearing-pyrazole-moiety-synthesis-and-biological-evaluation-as-possible-antibacterial-and-antifungal-agents
#15
Mohamed F El Shehry, Mostafa M Ghorab, Samir Y Abbas, Eman A Fayed, Said A Shedid, Yousry A Ammar
In an attempt for development of new antimicrobial agents, three series of quinoline derivatives bearing pyrazole moiety have been synthesized. The first series was synthesized through the synthesis of 4-(quinolin-2-yloxy)benzaldehyde and 4-(quinolin-2-yloxy)acetophenone and then treatment with ketone or aldehyde derivatives to afford the corresponding chalcones. Cyclization of the latter chalcones with hydrazine derivatives led to the formation of new pyrazoline derivatives. The second series was synthesized via the synthesis of 2-hydrazinylquinoline and then treatment with formylpyrazoles to afford the corresponding hydrazonyl pyrazole derivatives...
October 19, 2017: European Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/29112322/ab-initio-ligand-field-molecular-mechanics-and-the-nature-of-metal-ligand-%C3%AF-bonding-in-fe-ii-2-6-di-pyrazol-1-yl-pyridine-spin-crossover-complexes
#16
Robert James Deeth, Malcolm Halcrow, Laurence Kershaw Cook, Paul Raithby
A ligand field molecular mechanics (LFMM) force field has been constructed for the spin states of [Fe(bpp)₂]²+ (bpp = 2,6-di(pyrazol-1-yl)pyridine) and related complexes. A new charge scheme is employed which interpolates between partial charges for neutral bpp and protonated [H₃bpp]³+ to achieve a target metal charge. The LFMM angular overlap model (AOM) parameters are fitted to fully ab initio d orbital energies. However, several AOM parameters sets are possible. The ambiguity is resolved by calculating the Jahn-Teller distortion mode for high spin which indicates that in [Fe(bpp)₂]²+pyridine is a π acceptor and pyrazole a weak π donor...
November 7, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/29111607/an-incomplete-spin-transition-associated-with-a-z-1-%C3%A2-z-24-crystallographic-symmetry-breaking
#17
Izar Capel Berdiell, Rafal Kulmaczewski, Oscar Cespedes, Malcolm Andrew Halcrow
Crystalline [FeL₂][BF₄]₂·Me₂CO (L = N-[2,6-di{pyrazol-1-yl}pyrid-4-yl]acetamide) is high-spin at room temperature, and undergoes an abrupt, hysteretic spin-crossover at T½ = 137 K (ΔT½ = 14 K) that proceeds to ca 50 % completeness. This is associated with a crystallographic phase transition, from phase 1 (P21/c, Z = 4) to phase 2 (P21, Z = 48). The cations associate into chains in the crystal via weak intermolecular π…π interactions. Phase 2 contains a mixture of high-spin and low-spin molecules, which are grouped into triads along these chains...
November 7, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/29111513/a-hybrid-imidazolylidene-imidazolium-nickel-nhc-complex-an-isolated-intermediate
#18
Philipp J Altmann, Michael Ehrenreich, Alexander Pöthig
Macrocyclic ligand systems with a variety of (different) donor sites oftentimes give rise to very exciting and unexpected multinuclear metal complexes. We report herein the structure of a trinuclear mixed imidazolylidene/imidazolium nickel N-heterocyclic carbene (NHC) complex, namely di-μ-chlorido-bis{μ-calix[2]imidazolium[2]imidazolylidene[2]pyrazolate}trinickel(II) tetrakis(hexafluoridophosphate) acetonitrile tetrasolvate, [Ni3(C24H24N12)2Cl2](PF6)4·4CH3CN or [Ni3(L(Me))2Cl2](PF6)4·4CH3CN, that can be understood as a trapped reaction intermediate during the synthesis of the respective [Ni2L(Me)](PF6)2 product...
November 1, 2017: Acta Crystallographica. Section C, Structural Chemistry
https://www.readbyqxmd.com/read/29110989/repurposing-hsp90-inhibitors-as-antibiotics-targeting-histidine-kinases
#19
Chau D Vo, Hanna L Shebert, Shannon Zikovich, Rebecca A Dryer, Tony P Huang, Lindsey J Moran, Juno Cho, Douglas R Wassarman, Bryn E Falahee, Peter D Young, Garrick H Gu, James F Heinl, John W Hammond, Taylor N Jackvony, Thomas E Frederick, Jimmy A Blair
To address the growing need for new antimicrobial agents, we explored whether inhibition of bacterial signaling machinery could inhibit bacterial growth. Because bacteria rely on two-component signaling systems to respond to environmental changes, and because these systems are both highly conserved and mediated by histidine kinases, inhibiting histidine kinases may provide broad spectrum antimicrobial activity. The histidine kinase ATP binding domain is conserved with the ATPase domain of eukaryotic Hsp90 molecular chaperones...
October 19, 2017: Bioorganic & Medicinal Chemistry Letters
https://www.readbyqxmd.com/read/29110367/copper-or-thermally-induced-divergent-outcomes-synthesis-of-4-methyl-2h-chromenes-and-spiro-4h-pyrazoles
#20
Xinfang Xu, Yang Zheng, Kemiao Hong, Shanliang Dong, Lihua Qiu
An unprecedented divergent outcome transformation of alkyne tethered N-sulfonyl hydrazones is reported, which provides a direct and effective access to 4-methyl 2H-chromene derivatives and spiro-4H-pyrazoles in the presence of copper catalyst or under thermal conditions, respectively. The salient features of this process include readily available starting materials, inexpensive copper catalyst, mild reaction conditions, broad substrate scope, diverse transformations and potential applications of these generated products...
November 7, 2017: Chemistry: a European Journal
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