Showing papers on "Pyrazole published in 2016"
TL;DR: Owing to the development of novel and new pyrazole based therapeutic agents at a faster pace, there is a need to couple the latest information with previously available information to understand status of this moiety in medicinal chemistry research.
286 citations
TL;DR: This review throws light on the detailed synthetic approaches which have been applied for the synthesis of pyrazole and an in depth analysis of the pyrazoles with respect to their medical significance may help the medicinal chemists to generate new leads possessingPyrazole nucleus with high efficacy.
Abstract: Pyrazole are potent medicinal scaffolds and exhibit a full spectrum of biological activities. This review throws light on the detailed synthetic approaches which have been applied for the synthesis of pyrazole. This has been followed by an in depth analysis of the pyrazole with respect to their medical significance. This follow-up may help the medicinal chemists to generate new leads possessing pyrazole nucleus with high efficacy.
192 citations
TL;DR: An operationally simple and general method for copper-catalyzed, aminoquinoline-assisted amination of β-C(sp(2))-H bonds of benzoic acid derivatives is reported and Exceptionally high generality with respect to amine coupling partners is observed.
Abstract: An operationally simple and general method for copper-catalyzed, aminoquinoline-assisted amination of β-C(sp2)-H bonds of benzoic acid derivatives is reported. The reaction employs Cu(OAc)2 or (CuOH)2CO3 catalysts, an amine coupling partner, and oxygen from air as a terminal oxidant. Exceptionally high generality with respect to amine coupling partners is observed. Specifically, primary and secondary aliphatic and aromatic amines, heterocycles, such as indoles, pyrazole, and carbazole, sulfonamides, as well as electron-deficient aromatic and heteroaromatic amines are competent coupling components.
140 citations
TL;DR: The data about the synthesis and modification of heterocyclic systems with thiazolidine and pyrazoline or pyrazole fragments in molecules as promising objects of modern bioorganic and medicinal chemistry are summarized.
117 citations
TL;DR: In particular, the presence of a high field ligand such as an N -heterocyclic carbene in these compounds facilitates high energy emission, which results in the desired blue-colored light required for OLED applications as mentioned in this paper.
99 citations
TL;DR: Detailed quantitative structure-activity relationship (QSAR) analysis indicated the molecular parameters that contribute to increased potency of inhibition and would further encourage understanding in employing coumarin pyrazole hybrids as potential antibiotic agents for treating infections caused by pathogenic microbes and fungi.
97 citations
TL;DR: A new bifunctional squaramide organocatalyst derived from L-proline mediated the first enantioselective synthesis of dihydrospiro[indoline-3,4'-pyrano[2,3-c]pyrazole] derivatives in excellent enantiOSElectivity by reacting pyrazolones with isatylidine β,γ-unsaturated α-ketoester.
91 citations
TL;DR: Nine ionic derivatives of the N,N'-(3,6-dinitropyrazole-1,4-diyl)dinitramidate anion were prepared by acid-base reactions and fully characterized by infrared, multinuclear NMR spectra, and elemental analysis.
Abstract: A family of 3,6-dinitropyrazolo[4,3-c]pyrazole-based energetic compounds was synthesized by using versatile N-functionalization strategies. Subsequently, nine ionic derivatives of the N,N'-(3,6-dinitropyrazolo[4,3-c]pyrazole-1,4-diyl)dinitramidate anion were prepared by acid-base reactions and fully characterized by infrared, multinuclear NMR spectra, and elemental analysis. The structures of four of these compounds were further confirmed by single-crystal X-ray diffraction. Based on their different physical and detonation properties, these compounds exhibit promising potential as modern energetic materials and can be variously classified as green primary explosives, high-performance secondary explosives, fuel-rich propellants, and propellant oxidizers.
89 citations
TL;DR: A new sequence of pyrazole derivatives (1–6) was synthesized from condensation technique under utilizing ultrasound irradiation and the compound 2-((5-hydroxy-3-methyl-1H-pyrazol-4-yl)(4-nitrophenyl)methyl)hydrazinecarboxamide (4) was better activity against anti-inflammatory when compared with standard drugs (Diclofenac sodium).
75 citations
TL;DR: A series of Schiff bases of 4-amino-1,2,4-triazole derivatives containing pyrazole revealing significant analgesic and antioxidant properties were synthesized from condensation of 5-methyl-1H-pyrazol-3-yl derivative with various aromatic aldehydes.
Abstract: A series of Schiff bases of 4-amino-1,2,4-triazole derivatives containing pyrazole (5a-h) were synthesized from condensation of 4-amino-5-(5-methyl-1H-pyrazol-3-yl)-4H-1,2,4-triazole-3-thiol (3) derivative with various aromatic aldehydes (4a-h). The structures of the synthesized compounds were elucidated by IR, 1H NMR, 13C NMR, and mass spectrometry. All the synthesized compounds (5a-h) were screened for their in vivo analgesic and in vitro antioxidant activities revealing significant analgesic and antioxidant properties.
74 citations
TL;DR: In this paper, a powerful, magnetic, supported, acid catalyst, NiFe2O4@SiO2−H3PW12O40, was prepared by chemical support of Keggin (H3pW12o40) heteropolyacid (HPA) on silica-coated NiFe 2O4 magnetic nanoparticles.
Abstract: A powerful, magnetic, supported, acid catalyst, NiFe2O4@SiO2–H3PW12O40, was prepared by chemical support of Keggin (H3PW12O40) heteropolyacid (HPA) on silica-coated NiFe2O4 magnetic nanoparticles. XRD, TEM, SEM, VSM, and FTIR confirmed that the keggin HPA is well dispersed on the surface of silica-coated NiFe2O4 magnetic nanoparticles. The magnetically recoverable catalyst could be easily recycled at least six times without significant loss of catalytic activity. After full characterization, its catalytic activity was investigated in the synthesis of tetrahydrobenzo[b]pyran and pyrano[2,3-c]pyrazole derivatives. (1) Novel silica-coated magnetic NiFe2O4 nanoparticles-supported H3PW12O40 was fabricated and characterized. (2) Recyclability of the catalyst. (3) Avoiding use of corrosive acid catalysts. (4) Green chemistry.
TL;DR: In this paper, 6-nitropyrazolo[3,4d][1,2,3]triazol-3(4H)-olate anion was synthesized via a cyclization reaction of N-methyl or N,N′-ethylene substituted 4-chloro-3,5-dinitro pyrazole and hydrazine hydrate.
Abstract: Energetic salts based on the 6-nitropyrazolo[3,4-d][1,2,3]triazol-3(4H)-olate anion were synthesized via a cyclization reaction of N-methyl or N,N′-ethylene substituted 4-chloro-3,5-dinitro pyrazole and hydrazine hydrate. All energetic salts were well characterized by differential scanning calorimetry (DSC), elemental analyses, and IR and multinuclear NMR spectroscopy. Energetic properties, including density, detonation velocity and detonation pressure, were evaluated for these nitrogen-rich fused heterocycles as a family of new energetic materials.
TL;DR: In this paper, a nano-structured organo solid catalyst was used for the cascade synthesis of 1,8-dioxo-octahydroxanthene derivatives by the condensation reaction between dimedone and various aldehydes at 80°C under solvent-free conditions.
Abstract: Imidazole-based ionic liquid-stabilized on silica coated Fe 3 O 4 magnetic nano particles [nano-Fe 3 O 4 @SiO 2 @(CH 2 ) 3 -Imidazole-SO 3 H]Cl as a novel heterogeneous acidic catalyst was designed, synthesized and fully characterized by FT-IR, thermo gravimetric analysis (TGA), differential thermal analysis (DTA), energy-dispersive x-ray spectroscopy (EDX), X-ray diffraction patterns (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), Brunauer–Emmett–Teller (BET) and inductively coupled plasma (ICP) analysis. The nano-structured organo solid catalyst as a novel, mild and full-fledged catalyst was used for the cascade synthesis of 1,8-dioxo-octahydroxanthene derivatives by the condensation reaction between dimedone and various aldehydes at 80 °C under solvent-free conditions. Similarly, dihydropyrano[2,3- c ]pyrazole derivatives were synthesized by the one-pot three-component condensation reaction of aldehydes, malononitrile and 3-methyl-1-phenyl-2-pyrazoline-5-one under solvent-free conditions at room temperature. To the knowledge of our science, this is the main investigation on the synthesis of [nano-Fe 3 O 4 @SiO 2 @(CH 2 ) 3 -Imidazole-SO 3 H]Cl as a worthy heterogeneous nano magnetic solid acid for acid catalyzed organic reactions.
TL;DR: A series of pyrazole substituted 1.3-diketones bearing fluorinated alkyl groups were prepared and systematically explored as a ligands for the preparation of luminescent complexes with Eu(III) ion.
TL;DR: A series of thiazoles bearing pyrazole as a possible pharmacophore were synthesized and assessed for their anti inflammatory activity using in vitro and in vivo methods, and molecular docking results revealed significant interactions of the test compounds with the active site of COX-II.
TL;DR: Bovine serum albumin (BSA) catalyzed synthesis of dihydropyrano[2,3-c]pyrazole derivatives via a one pot, three component reaction of an aldehyde/ketone/isatin, malononitrile and 3-methyl-1H-pyrazol-5-(4H)-one in H2O-EtOH (7
Abstract: Bovine serum albumin (BSA) catalyzed synthesis of dihydropyrano[2,3-c]pyrazole derivatives via a one pot, three component reaction of an aldehyde/ketone/isatin, malononitrile and 3-methyl-1H-pyrazol-5-(4H)-one in H2O–EtOH (7 : 3) at ambient temperature was developed in this work. The catalyst was found to work efficiently for aldehydes, ketones and isatins to give the corresponding dihydropyrano[2,3-c]pyrazole and spiro[indoline-3,4′-pyrano[2,3-c]pyrazole] derivatives in high yields. BSA showed a broad range of catalytic promiscuity towards various aldehydes, aromatic/aliphatic ketones and substituted isatins. The use of an environmentally benign protocol, reusability of the catalyst, avoidance of hazardous solvents, excellent yields, easy work up and no byproduct formation make BSA an attractive candidate for further applications as a biocatalyst.
TL;DR: In this article, a series of 1,3,4-thiadiazole with pyrazole-3-carboxamides (3a-f ) and pyrrole-3carboxamide (4a- f ) moiety are prepared using intermediate compounds 1, 3,4thiadiadiazolacrylamides (2a-F ).
TL;DR: A series of novel pyrazole amide derivatives were designed and synthesized by multi-step reactions from phenylhydrazine and ethyl 3-oxobutanoate as starting materials, and their structures were characterized by NMR, MS and elemental analysis.
Abstract: A series of novel pyrazole amide derivatives were designed and synthesized by multi-step reactions from phenylhydrazine and ethyl 3-oxobutanoate as starting materials, and their structures were characterized by NMR, MS and elemental analysis. The antifungal activity of the title compounds was determined. The results indicated that some of title compounds exhibited moderate antifungal activity. Furthermore, DFT calculations were used to study the structure-activity relationships (SAR).
TL;DR: A series of novel chiral fluorinated pyrazole carboxamides derivatives were designed and synthesized and some of them exhibited good control efficacy against the tomato root-knot nematode disease caused by Meloidogyne incognita.
TL;DR: 2-Aminophenyl-1H-pyrazole was discovered as a removable bidentate directing group for copper-mediated aerobic oxidative C(sp(2)-H) bond amidation and sulfonamidation and has proven to be particularly efficient in C-H sulfon amidation.
TL;DR: A novel efficient tandem reaction of hydrazones and α-bromo ketones and intramolecular cyclization under mild conditions with wide group tolerance provides a potential approach to the 1,3,5-trisubstituted pyrazoles.
Abstract: A novel efficient tandem reaction of hydrazones and α-bromo ketones is reported for the preparation of 1,3,5-trisubstituted pyrazoles by visible light catalysis. In this system, the monosubstituted hydrazones show wonderful reaction activity with alkyl radicals, generated from α-bromo ketones. A radical addition followed by intramolecular cyclization affords the important pyrazole skeleton in good to excellent yields. This efficient strategy under mild conditions with wide group tolerance provides a potential approach to the 1,3,5-trisubstituted pyrazoles.
TL;DR: The present method should provide a useful strategy for the construction of different thiol-substituted pyrazole motifs for the synthesis of C-4 sulfenylated pyrazoles.
Abstract: A green and efficient iodine-catalyzed cross-dehydrogenative C–S coupling method for the synthesis of C-4 sulfenylated pyrazoles has been initially developed under metal-free conditions. This new method is highly efficient and practical, and the starting materials are readily available. The present method should provide a useful strategy for the construction of different thiol-substituted pyrazole motifs.
TL;DR: Two compounds 16 and 27 have been identified as promising new molecules that have the potential to be developed as leads for CDK1/Cdc2 inhibitors against human cancer cell lines.
TL;DR: Compound 5a is more effective with ED50 = 0.98 and 3.98 μM against COX-2 and 15-lipoxygenase respectively, than the references celecoxib and meclofenamate sodium, while 2D NMR determinations show Cyclization of different pyrazoles was discussed using HSQC, HMBC and NOSEY determinations.
TL;DR: In this paper, a new approach for fine tuning the properties of energetic compounds through bonding of energetic pyrazoles with tetrazole moieties by means of N,N′-ethylene bridges is described.
Abstract: A new approach for fine tuning the properties of energetic compounds through bonding of energetic pyrazoles with tetrazole moieties by means of N,N′-ethylene bridges is described. Reactions of various pyrazole derivatives with 2-haloethylamines, followed by reaction with cyanogen azide resulted in the formation of compounds having ethylene-bridged 5-aminotetrazole and nitropyrazole. Further reactions on this basic framework resulted in various energetic compounds having mono, di or tri nitro-substituted pyrazole moieties, and an amino or nitroimino-substituted tetrazole ring. All the compounds were thoroughly characterized by IR, and NMR [1H, 13C{1H}, 15N] spectra, elemental analysis, and differential scanning calorimetry (DSC). Some of them were also structurally characterized with single-crystal X-ray diffraction studies. Heats of formation and detonation performance for all the energetic compounds were calculated using Gaussian 03 and EXPLO5 v6.01 programs, respectively. Initial studies showed that the properties of energetic compounds can indeed be fine-tuned by careful selection of the number and nature of energetic groups on the pyrazole and tetrazole rings.
TL;DR: It is shown that introduction of the trifluoromethyl group into the pyrazolyl ring is helpful for enhancing the luminescence properties of Cu(i) pyrazole phosphine complexes.
Abstract: A family of new dinuclear Cu(i) complexes with 1,4-bis(diphenylphosphino)butane (dppb) and functionalized 3-(2'-pyridyl)pyrazole mixed ligands has been synthesized and characterized. It is revealed that all these Cu(i) complexes include a [Cu2(dppb)2](2+) framework with the two Cu(i) atoms doubly bridged by a pair of dppb to generate a fourteen-membered Cu2P4C8 ring, and functionalized 3-(2'-pyridyl)pyrazole adopts a neutral chelating coordination mode without the N-H bond cleavage of the pyrazolyl ring. All these dinuclear Cu(i) complexes display a relatively weak low-energy absorption in CH2Cl2 solution, which is closely related to the variation of the Cu-N and Cu-P bonds caused by the substituent on the pyrazolyl ring. These dinuclear Cu(i) complexes are all emissive in solution and solid states at ambient temperature, which can be well modulated through structural modification of 3-(2'-pyridyl)pyrazole. It is shown that introduction of the trifluoromethyl group into the pyrazolyl ring is helpful for enhancing the luminescence properties of Cu(i) pyrazole phosphine complexes.
TL;DR: A new library of 1,3,4-thiadiazole-containing pyrazole oximes was designed and synthesized and results indicated that some target compounds exhibited good acaricidal and insecticidal properties.
TL;DR: This is the first report of exploring Lewis acid properties of MoO2Cl2 in the diversity oriented synthesis of Biginelli and Hantzsch reactions and demonstrates the exceptional tolerance towards acid labile protecting groups such as tert-butyl dimethyl silyl (TBDMS).
Abstract: A simple, facile and efficient synthesis of functionalized dihydropyrimidinones and polyhydroquinolines using molybdenum(VI) dichloride dioxide (MoO2Cl2) has been developed. The present protocol demonstrates the exceptional tolerance towards acid labile protecting groups such as tert-butyl dimethyl silyl (TBDMS) and tert-butyl diphenyl silyl (TBDPS). This is the first report of exploring Lewis acid properties of MoO2Cl2 in the diversity oriented synthesis of Biginelli and Hantzsch reactions. Biologically important and highly structured conjugates of dihydropyrimidinone and polyhydroquinoline derivatives containing coumarin, pyrazole, indole and triazole moieties were synthesized in good to excellent yields. Compound 4o exhibited blue fluorescence at a maximum UV absorbance λmax of 326 nm. In the preliminary MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay, compound 4n displayed remarkable cytotoxic activity against A549 and PC3 cell lines while compound 7q was found to be cytotoxic against HGC-27 and PC3 cancer cell lines.
TL;DR: A modular synthetic route to combretastatin analogs based on a pyrazole core through highly regioselective alkyne cycloaddition reactions of sydnones is developed, showing modest to high potency against human umbilical vein endothelial cell proliferation.
Abstract: The combretastatins are an important class of tubulin-binding agents. Of this family, a number of compounds are potent tumor vascular disrupting agents (VDAs) and have shown promise in the clinic for cancer therapy. We have developed a modular synthetic route to combretastatin analogs based on a pyrazole core through highly regioselective alkyne cycloaddition reactions of sydnones. These compounds show modest to high potency against human umbilical vein endothelial cell proliferation. Moreover, evidence is presented that these novel VDAs have the same mode of action as CA4P and bind reversibly to β-tubulin, believed to be a key feature in avoiding toxicity. The most active compound from in vitro studies was taken forward to an in vivo model and instigated an increase in tumor cell necrosis.
TL;DR: In this article, an efficient synthesis of pyrazole derivatives catalyzed by a dioxomolybdenum complex supported on functionalized Fe3O4 magnetite nanoparticles containing a Schiff base ligand is reported.
Abstract: Efficient synthesis of pyrazole derivatives catalyzed by a dioxomolybdenum complex supported on functionalized Fe3O4 magnetite nanoparticles containing a Schiff base ligand is reported The synthesized catalyst was characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), vibrating sample magnetometry (VSM), inductively coupled plasma atomic emission spectroscopy (ICP-AES) and Fourier transform infrared spectroscopy (FT-IR) This heterogeneous catalyst can be reused several times without significant loss of its catalytic activity The described metal-complex immobilized on MNPs catalyst was efficiently tested in the synthesis of pyrazole derivatives via three-component condensation of aromatic aldehydes, malononitrile and phenylhydrazine with short reaction times and good yields and also ease of separation, recycling and reusability of catalyst Besides, the catalyst could be recovered in a facile manner from the reaction mixture and recycled eight times without loss in activity Also, a mechanistic approach was proposed for the final step of the synthesis of pyrazole derivatives which was supported by theoretical studies