Showing papers on "Pyrazole published in 2012"
TL;DR: Three areas are discussed, that is pyrazole metal complexes as: (i) anticancer, (ii) antibacterial/parasitic and (iii) antiviral agents.
Abstract: Pyrazoles are widely used as core motifs for a large number of compounds for various applications such as catalysis, agro-chemicals, building blocks of other compounds and in medicine. The attractiveness of pyrazole and its derivatives is their versatility that allows for synthesis of a series of analogues with different moieties in them, thus affecting the electronics and by extension the properties of the resultant compounds. In medicine pyrazole is found as a pharmacophore in some of the active biological molecules. While pyrazole derivatives have been extensively studied for many applications including anticancer, antimicrobial, anti-inflammatory, antiglycemic, anti-allergy and antiviral, much less has been reported on their metal counterparts in spite of the fact that metals have been shown to impart activity to ligands. Thus this perspective is intended to demonstrate the potential of pyrazole and pyrazolyl metal complexes in the areas of drug discovery and development. Several examples, that include palladium, platinum, copper, gold, zinc, cobalt, nickel, iron, copper, silver and gallium complexes, are used to bolster the above point. For the purposes of this review three areas are discussed, that is pyrazole metal complexes as: (i) anticancer, (ii) antibacterial/parasitic and (iii) antiviral agents.
182 citations
TL;DR: This one-pot synthesis of spiro[indoline-3,4'-pyrano[2,3-c]pyrazole] derivatives by four-component reaction of hydrazine, β-keto ester, isatin, and malononitrile catalyzed by piperidine under ultrasound irradiation is described.
Abstract: An efficient one-pot synthesis of spiro[indoline-3,4′-pyrano[2,3-c]pyrazole] derivatives by four-component reaction of hydrazine, β-keto ester, isatin, and malononitrile or ethyl cyanoacetate catalyzed by piperidine under ultrasound irradiation is described. This synthesis was confirmed to follow the group-assistant-purification chemistry (GAP) chemistry process, which can avoid traditional chromatography and recrystallization purifications.
147 citations
TL;DR: Two new Schiff bases of 1,3-diphenyl-1H-pyrazole-4-carboxaldehyde and 4-amino-5-mercapto-3-methyl/H-1,2,4-triazole and their Cobalt, Nickel, Copper and Zinc complexes have been synthesized and characterized by elemental analyses, spectral studies, thermal techniques and magnetic measurements.
125 citations
TL;DR: New pyrazole and pyrazoline derivatives have been synthesized and their ability to inhibit ovine COX-1/COX-2 isozymes was evaluated using in vitro cyclooxygenase (COX) inhibition assay, and the anti-inflammatory activity of selected compounds was investigated in vivo using carrageenan-induced rat paw edema model.
121 citations
TL;DR: The synthesis and pharmacological activity of a new series of 1-aryl pyrazoles as potent σ1 receptor (σ1R) antagonists are reported in this paper. But the nature of the pyrazole substituents was crucial for activity, and a basic amine was shown to be necessary, in accordance with known receptor pharmacophores.
Abstract: The synthesis and pharmacological activity of a new series of 1-arylpyrazoles as potent σ1 receptor (σ1R) antagonists are reported. The new compounds were evaluated in vitro in human σ1R and guinea pig σ2 receptor (σ2R) binding assays. The nature of the pyrazole substituents was crucial for activity, and a basic amine was shown to be necessary, in accordance with known receptor pharmacophores. A wide variety of amines and spacer lengths between the amino and pyrazole groups were tolerated, but only the ethylenoxy spacer and small cyclic amines provided compounds with sufficient selectivity for σ1R vs σ2R. The most selective compounds were further profiled, and compound 28, 4-{2-[5-methyl-1-(naphthalen-2-yl)-1H-pyrazol-3-yloxy]ethyl}morpholine (S1RA, E-52862), which showed high activity in the mouse capsaicin model of neurogenic pain, emerged as the most interesting candidate. In addition, compound 28 exerted dose-dependent antinociceptive effects in several neuropathic pain models. This, together with its...
114 citations
TL;DR: A novel, one-pot, simple, efficient procedure for 4H-pyrimido[2,1-b]benzothiazole, pyrazole, and benzylidene derivatives of curcumin under solvent and solvent free conditions in microwave with good yield is synthesized.
102 citations
TL;DR: The results suggest that hydrazones, 2-azetidinones and 4-thiazolidinones bearing a core pyrazole scaffold would be potent antimicrobial and antitubercular agents.
101 citations
TL;DR: The CoMFA model revealed that a bulky and negatively charged group at the 4-position of benzene could enhance insecticidal activity, which could provide useful information for the design of novel insecticide containing substructural units of pyrazole amide and hydrazone.
Abstract: BACKGROUND: Pyrazole and hydrazone derivatives possess good insecticidal activities; their substructural units are widely used in pesticide design. In an effort to discover new molecules with good insecticidal activities, a series of pyrazole amide derivatives containing hydrazone substructures were synthesised and bioassayed. RESULTS: Bioassays demonstrated that some of the title compounds exhibited notable control of Plutellaxylostella (Linnaeus), Helicoverpa armigera (H ¨ ubner), Culex pipiens pallens, Laphygma exigua (H ¨ ubner), Spodoptera litura (Fabricius), Nilaparvata lugens (Stal) and Rhopalosiphum maidis (Fitch) at 5, 10, 0.25, 200, 20, 100 and 500 mg L −1 respectively. Comparative molecular field analysis (CoMFA) based on the bioactivities forP.xylostella was studied; the values ofq 2 andr 2 for the CoMFA model were 0.701 and 0.964 respectively. CONCLUSION: Some of the title compounds displayed good and broad-spectrum insecticidal activities against different insect species; the CoMFA model revealed that a bulky and negatively charged group at the 4-position of benzene could enhance insecticidal activity. These results could provide useful information for the design of novel insecticide containing substructural units of pyrazole amide and hydrazone. c � 2011 Society of Chemical Industry Supportinginformationmaybefoundintheonlineversionofthisarticle.
97 citations
TL;DR: An efficient one-pot synthesis in multi-component system (MRCs) for the preparation of pyrazolo[3,4-b]pyridine derivatives from the reaction of 5-amino-1-phenyl-3-(pyridin-3-yl)-1H-pyrazole with 4-anisaldehyde and p-substituted β-ketonitriles with antifungal activity against Fusarium Oxysporum
93 citations
TL;DR: A series of Au(I) and Au(III) mono-, homobis-, and heterobis(carbene) complexes, [AuCl(FPyr)] (2), [auCl3(iPr2-bimy)] (6),...
91 citations
TL;DR: A novel combinatorial library of S-substituted-1,3,4-oxadiazole bearing N-methyl-4-(trifluoromethyl)phenyl pyrazole moiety is designed and synthesized and tested for in-vitro cytotoxic activity by MTT assay.
TL;DR: The use of water as solvent and indium trichloride as promoter for the three-component combinatorial synthesis of a variety of bioactive pyrimidine and pyrazole derivatives (2, 10) from aldehydes, 1,3-dicarbonyl compounds, and electron-rich amino heterocycles like 6-amino-1,3dimethyl uracil and 3-methyl-1-phenyl-1H-pyrazol-5-amine catalyzed by indium-tricide under reflux has
TL;DR: The regioselective synthesis of pyrazole triflones has been achieved by 1,3-dipolar cycloaddition of triflyl alkynes and hydrazonoyl chloride in the presence of Hünig's base.
TL;DR: A green and efficient one-pot, four-component synthesis of methyl 6-amino-5-cyano-4-aryl-2,4-dihydropyrano[2,3-c]pyrazole-3-carboxylates in water is described in this paper.
TL;DR: Sixteen novel pyrazole acyl thiourea derivatives 6 were synthesized from monomethylhydrazine and ethyl acetoacetate and some of the synthesized compounds displayed good antifungal activities against Gibberella zeae, Fusarium oxysporum, Cytospora mandshurica and anti-TMV activity in preliminary antIFungal activity tests.
Abstract: Sixteen novel pyrazole acyl thiourea derivatives 6 were synthesized from monomethylhydrazine (phenylhydrazine) and ethyl acetoacetate. The key 5-chloro-3-methyl-1-substituted-1H-pyrazole-4-carbonyl chloride intermediates 4 were first generated in four steps through cyclization, formylation, oxidation and acylation. Thess were then reacted with ammonium thiocyanate in the presence of PEG-400 to afford 5-chloro-3-methyl-1-substituted-1H-pyrazole-4-carbonyl isothiocyanates 5. Subsequent reaction with fluorinated aromatic amines resulted in the formation of the title compounds. The synthesized compound were unequivocally characterized by IR, ¹H-NMR, ¹³C-NMR and elemental analysis and some of the synthesized compounds displayed good antifungal activities against Gibberella zeae, Fusarium oxysporum, Cytospora mandshurica and anti-TMV activity in preliminary antifungal activity tests.
TL;DR: An efficient two-step synthesis of pyrazoline ligand is described which is an effective "turn on" fluorescent sensor for Cd(2+) in MeCN.
Abstract: An efficient two-step synthesis of pyrazoline ligand 1 is described which is an effective “turn on” fluorescent sensor for Cd2+ in MeCN. Oxidation to the corresponding pyrazole ligand 2 creates a “turn on” fluorescent sensor now selective for Zn2+ and able to distinguish it from Cd2+.
TL;DR: In the present study, a series of 1,3-diaryl pyrazole derivatives bearing rhodanine-3-fatty acid moieties were synthesized and their antimicrobial activities were tested against various Gram-positive and Gram-negative bacteria.
TL;DR: The synthesized compounds showed potent inhibitory action against the test organisms and were screened for in vitro antibacterial activity against the representative panel of Gram-positive and Gram-negative bacteria.
TL;DR: The important features identified in the 3D-QSAR models have been used to propose new molecules whose activities are predicted higher than the existing systems and provide valuable directions to the ongoing endeavor of rationally designing more potent antitubercular agents.
TL;DR: The stronger the Lewis acidity (Z(eff)/r) of the metal ion, the more acidic is the M(II)-coordinated water and the greater is the propensity of theMetal ion to catalyze hydrolysis of the phosphate ester HPNP.
Abstract: Using the dinucleating phenol-based ligand 2,6-bis[3-(pyridin-2-yl)pyrazol-1-ylmethyl]-4-methylphenol] (HL2), in its deprotonated form, the six new dinuclear complexes [MII2(L2)(μ-O2CMe)2(MeCN)2][PF6] (M = Mn (2a), Co (3a), Zn (4a)) and [MII2(L2)(μ-O2CMe)2(MeCN)2][BPh4] (M = Mn (2b), Co (3b), Zn (4b)) have been synthesized. Crystallographic analyses on 2b·2MeCN, 3b·2MeCN, and 4b·2MeCN reveal that these complexes have closely similar μ-phenoxo bis(μ-carboxylato) structures. The physicochemical properties (absorption and ESI-MS spectral data, 2a,b, 3a,b, and 4a,b; 1H NMR, 4a,b) of the cations of 2a–4a are identical with those of 2b–4b. Each metal ion is terminally coordinated by a pyrazole nitrogen and a pyridyl nitrogen from a 3-(pyridin-2-yl)pyrazole unit and a solvent molecule (MeCN). Thus, each metal center assumes distorted-octahedral MIIN3O3 coordination. Temperature-dependent magnetic studies on MnII and CoII dimers reveal the presence of intramolecular antiferromagnetic (J = −8.5 cm–1) for 2b and fe...
TL;DR: In search for a new antioxidant and antimicrobial agent with improved potency, a series of benzofuran based 1,3,5-substituted pyrazole analogues (5a-l) in five step reaction are synthesized.
TL;DR: The antimicrobial activity of the newly isolated heterocyclic compounds was evaluated against Gram-positive, Gram-negative bacteria and fungi and most of the compounds showed a moderate degree of potent antimacterial activity.
Abstract: Reaction of a series of (E)-3-phenyl-4-(p-substituted phenyl)-3-buten-2-ones with p-sulfamylphenyl hydrazine in glacial acetic acid gave the corresponding hydrazones, subsequent treatment of which with 30% HCl afforded pyrazole-1-sulphonamides On the other hand, refluxing of chalcones with either thiosemicarbazide or isonicotinic acid hydrazide in ethanol containing a few drops of acetic acid gave pyrazoline-1-thiocarboxamides and isonicotinoyl pyrazolines, respectively The structures of the synthesized compounds were determined on the basis of their elemental analyses and spectroscopic data The antimicrobial activity of the newly isolated heterocyclic compounds was evaluated against Gram-positive, Gram-negative bacteria and fungi Most of the compounds showed a moderate degree of potent antimicrobial activity
TL;DR: Biological evaluation study showed, the compounds 4, 5, 9, 11, 14 and 16 found to have promising anti-inflammatory activity at concentration of 10 μM with reference to standard dexamethasone (76% TNF-α and 86% IL-6 inhibitory activity at 1 μM).
TL;DR: The cytotoxicity of the newly synthesized heterocyclic steroids against three human tumor cell lines namely breast adenocarcinoma, non-small cell lung cancer and CNS cancer were studied and some of tested compounds were found to exhibit much higher inhibitory effects towards the three tumor cell Lines than the reference drug, doxorubicin.
TL;DR: To analyse how an aqueous medium can influence the mechanism of the bifunctional catalytic process, DFT calculations (B3LYP) including one or two explicit water molecules and using the polarisable continuum model have been carried out and provide a valuable insight into the role of water on the activity of the B2B catalyst.
Abstract: The catalytic activity of ruthenium(IV) ([Ru(η(3):η(3)-C(10)H(16))Cl(2)L]; C(10)H(16) = 2,7-dimethylocta-2,6-diene-1,8-diyl, L = pyrazole, 3-methylpyrazole, 3,5-dimethylpyrazole, 3-methyl-5-phenylpyrazole, 2-(1H-pyrazol-3-yl)phenol or indazole) and ruthenium(II) complexes ([Ru(η(6)-arene)Cl(2)(3,5-dimethylpyrazole)]; arene = C(6)H(6), p-cymene or C(6)Me(6)) in the redox isomerisation of allylic alcohols into carbonyl compounds in water is reported. The former show much higher catalytic activity than ruthenium(II) complexes. In particular, a variety of allylic alcohols have been quantitatively isomerised by using [Ru(η(3):η(3)-C(10)H(16))Cl(2)(pyrazole)] as a catalyst; the reactions proceeded faster in water than in THF, and in the absence of base. The isomerisations of monosubstituted alcohols take place rapidly (10-60 min, turn-over frequency = 750-3000 h(-1)) and, in some cases, at 35 °C in 60 min. The nature of the aqueous species formed in water by this complex has been analysed by ESI-MS. To analyse how an aqueous medium can influence the mechanism of the bifunctional catalytic process, DFT calculations (B3LYP) including one or two explicit water molecules and using the polarisable continuum model have been carried out and provide a valuable insight into the role of water on the activity of the bifunctional catalyst. Several mechanisms have been considered and imply the formation of aqua complexes and their deprotonated species generated from [Ru(η(3):η(3)-C(10)H(16))Cl(2)(pyrazole)]. Different competitive pathways based on outer-sphere mechanisms, which imply hydrogen-transfer processes, have been analysed. The overall isomerisation implies two hydrogen-transfer steps from the substrate to the catalyst and subsequent transfer back to the substrate. In addition to the conventional Noyori outer-sphere mechanism, which involves the pyrazolide ligand, a new mechanism with a hydroxopyrazole complex as the active species can be at work in water. The possibility of formation of an enol, which isomerises easily to the keto form in water, also contributes to the efficiency in water.
TL;DR: Three new pyrazole derivatives were synthesised and their antitumor activities against A549 and NCIH23 lung cancer cells were validated, resulting in compound 10, which has low (if any) cytotoxic activity and high potential cytostatic activity.
TL;DR: Addition of organic azides, N(3)R (R = 2,4,6-trimethylphenyl (Mes), phenyl (Ph), 1-adamantyl (Ad), results in the formation of a family of uranium(iv) imido derivatives, Tp*(2)U(NR) (2-R), which were synthesized in high yields by coupling of the benzyl groups to form bibenzyl.
Abstract: Addition of organic azides, N3R (R = 2,4,6-trimethylphenyl (Mes), phenyl (Ph), 1-adamantyl (Ad)), to a solution of the uranium(III) alkyl complex, Tp*2U(CH2Ph) (Tp* = hydrotris(3,5-dimethylpyrazolyl)borate) (1), results in the formation of a family of uranium(IV) imido derivatives, Tp*2U(NR) (2-R). Notably, these complexes were synthesized in high yields by coupling of the benzyl groups to form bibenzyl. The uranium(IV) imido derivatives, 2-Mes, 2-Ph, and 2-Ad, were all characterized by both 1H NMR and IR spectroscopy, and 2-Mes and 2-Ad were also characterized by X-ray crystallography. In the molecular structure of 2-Mes, typical κ3-coordination of the Tp* ligands was observed; however in the case of 2-Ad, one pyrazole ring of a Tp* ligand has rotated away from the metal centre, forcing a κ2-coordination of the pyrazoles. This results in a uranium–hydrogen interaction with the Tp* B–H. Treating these imido complexes with para-tolualdehyde results in multiple bond metathesis, forming the terminal uranium(IV) oxo complex, Tp*2U(O), and the corresponding imine.
TL;DR: A new metal-ligand bifunctional, pincer-type ruthenium complex featuring two proton-delivering pyrazole arms and a tautomeric form different from L1-H(2) in 1 and the central pyridine remained uncoordinated is synthesized.
Abstract: A new metal-ligand bifunctional, pincer-type ruthenium complex [RuCl(L1-H(2))(PPh(3))(2)]Cl (1; L1-H(2)=2,6-bis(5-tert-butyl-1H-pyrazol-3-yl)pyridine) featuring two proton-delivering pyrazole arms has been synthesized. Complex 1, derived from [RuCl(2)(PPh(3))(3)] with L1-H(2), underwent reversible deprotonation with potassium carbonate to afford the pyrazolato-pyrazole complex [RuCl(L1-H)(PPh(3))(2)] (2). Further deprotonation of 1 and 2 with potassium hexamethyldisilazide in methanol resulted in the formation of the bis(pyrazolato) complex [Ru(L1)(MeOH)(PPh(3))(2)] (3). Complex 3 smoothly reacted with dioxygen and dinitrogen to give the side-on peroxo complex [Ru(L1)(O(2))(PPh(3))(2)] (4) and end-on dinitrogen complex [Ru(L1)(N(2))(PPh(3))(2)] (5), respectively. On the other hand, the reaction of [RuCl(2)(PPh(3))(3)] with less hindered 2,6-di(1H-pyrazol-3-yl)pyridine (L3-H(2)) led to the formation of the dinuclear complex [{RuCl(2)(PPh(3))(2)}(2)(μ(2)-L3-H(2))(2)] (6), in which the pyrazole-based ligand adopted a tautomeric form different from L1-H(2) in 1 and the central pyridine remained uncoordinated. The detailed structures of 1-6 were determined by X-ray crystallography.
TL;DR: In this paper, a newly developed and structurally characterized vanadium complex [VO2F(dmpz)2] (Dmpz = 3, 5 dimethyl pyrazole) is reported as a recyclable catalyst for the selective oxidation of organic sulfides with H2O2 in CH3CN at sub-ambient temperature.
TL;DR: Ruthenium(II) complexes bearing a pyrazolyl-pyridyl-pyrazole ligand were synthesized and exhibited exceptionally high catalytic activity in the transfer hydrogenation of ketones in refluxing isopro...