Pyrazolo

Distribution by Scientific Domains
Distribution within Chemistry

Kinds of Pyrazolo

  • new pyrazolo
  • novel pyrazolo


  • Selected Abstracts


    Comparison between the Photophysical Properties of Pyrazolo- and Isoxazolo[60]fullerenes with Dual Donors (Ferrocene, Aniline and Alkoxyphenyl)

    EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 13 2007
    Laura Perez
    Abstract Two series of new pyrazolo- and isoxazolo[60]fullerenes covalently linked to vinylenephenylene bearing ferrocene, dibutylaniline or dodecyloxyphenyl electron-donor groups attached in the periphery have been synthesized. The photophysical properties of these newly synthesized dual-donor,C60 derivatives have been investigated and compared by applying time-resolved fluorescence and nanosecond transient techniques in both polar and nonpolar solvents. Charge separation via the excited singlet state of C60 is more efficient in the pyrazolo-C60 triads than in the isoxazolo-C60 triads. It was found that the pyrazoline ring mediates charge separation as a result of the stronger electron-donating character of the nitrogen atom of the pyrazoline ring compared with the oxygen atom of the isoxazoline ring. ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source]


    Syntheses of some new 1H -pyrazole, pyridazin-3(2H)-one, and oxazin-4-one derivatives

    HETEROATOM CHEMISTRY, Issue 1 2006
    Esvet Akba
    The new 1H-pyrazole-3-carboxylic acid 2, pyridazin-3(2H)-one 3, and their various derivatives were prepared by the reactions of the 4-benzoyl-5-phenyl-2,3-dihydro-2,3-furandione 1 and 2,5-dichlorophenylhydrazine. Pyrazolo[3,4-d]pyridazine 7 was obtained from cyclization of the pyrazole-3-carboxylic acid 2 with 2,5-dichlorophenylhydrazine. The reaction of 1 and pyrazole-3-carbonitriles 6 gave the new oxazin-4-one 9 derivatives. The structures of compounds were characterized on the basis of elemental analyses, mass, IR, 1H, and 13C NMR spectra. 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:8,12, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20170 [source]


    Pyrazolo,pyrimidine-derived c-Src inhibitor reduces angiogenesis and survival of squamous carcinoma cells by suppressing vascular endothelial growth factor production and signaling

    INTERNATIONAL JOURNAL OF CANCER, Issue 5 2007
    Sandra Donnini
    Abstract Src tyrosine kinase family cooperates with activated growth factor receptors to regulate growth, invasion and metastasis. The authors examined the influence of a novel c-Src inhibitor, 1l, derived from 4-amino-substituted-pyrazolo,pyrimidines, on tumor angiogenesis and on the angiogenic output of squamous carcinoma cells, A431 and SCC-4. The effect of 1l was assessed on growth and microvessel density in A431 tumors and its effect compared with the established c-Src inhibitor PP-1. The effects of c-Src inhibition were investigated on vascular endothelial growth factor (VEGF) expression and activity in tumor cells grown in vivo and in vitro, as well as on VEGF mediated signaling and on endothelial cell functions. Nanomolar concentrations of 1l decreased tumor volume promoted by A431 implanted in nude mice, without affecting in vitro cell tumor survival. This effect was related to 1l inhibition of VEGF production, and secondary to an effect on tumor microvessel density. The rabbit cornea assay confirmed that 1l markedly decreased neovessel growth induced by VEGF. In cultured endothelial cells, 1l inhibited the VEGF-induced phosphorylation on tyr416 of c-Src, resulting in a reduced cell proliferation and invasion. Consistently, 1l dowregulated endothelial nitric oxide synthase, MAPK-extracellular receptor kinase 1,2 (ERK1-2) activity and matrix metalloproteinases (MMP-2/MMP-9), while the tissue inhibitors of metalloproteinases (TIMP2/TIMP-1) were upregulated. These results demonstrate that nM concentrations of c-Src kinase inhibitors (1l and PP-1), by reducing the production of VEGF released by tumor cell and its endothelial cell responses, have a highly selective antiangiogenesis effect, which might be useful in combination therapies. 2006 Wiley-Liss, Inc. [source]


    Facile Assembly of H -Pyrazolo[5,1- a]isoquinolines via Silver Triflate-Catalyzed One-Pot Tandem Reaction of 2-Alkynyl- benzaldehyde, Sulfonohydrazide, and Ketone or Aldehyde

    ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 11-12 2010
    Xingxin Yu
    Abstract A novel and efficient route for the generation of H -pyrazolo[5,1- a]isoquinolines via silver triflate-catalyzed one-pot tandem reaction of 2-alkynylbenzaldehyde, sulfonohydrazide, and ketone or aldehyde is described. This reaction proceeds with good functional group tolerance under mild conditions with high efficiency and excellent selectivity. [source]


    First Copper-Catalyzed Intramolecular Amidation in Substituted 4-Iodopyrazoles Leading to the Synthesis of Pyrazolo[4,3- b]- pyridin-5-ones,

    ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 16 2009
    Somnath Nag
    Abstract An unprecedented copper-catalyzed intramolecular amidation of substituted 4-iodopyrazoles generated either via Baylis,Hillman or Horner,Wadsworth,Emmons chemistry for the synthesis of pyrazolo[4,3- b]pyridine-5-ones is described. In addition, the effect of the stereochemistry of the acrylamide on the cross-coupling reaction has been investigated and it is demonstrated that only the Z-isomer is favoured to undergo the intramolecular cyclization. [source]


    Studies on the reactions of cyclic oxalyl compounds with hydrazines or hydrazones : Synthesis and reactions of 4-benzoyl-1-(3-nitrophenyl)-5-phenyl-1H -pyrazole-3-carboxylic acid

    JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 5 2002
    Ahmet, ener
    The 1H -pyrazole-3-carboxylic acid 2, obtained from the furan-2,3-dione 1 and N -Benzylidene- N'-(3-nitrophenyl) hydrazine, was converted via reactions of its acid chloride 3 with various alcohols or N-nucleo-philes into the corresponding ester or amide derivatives 4 or 5, respectively. Nitrile 6 and anilino-pyrazole acid 7 derivatives of 2 were also obtained by dehydration of 5a in a mixture of SOCl2 with DMF and reduction of 2 with sodium polysulphide, respectively. While cyclocondensation reactions of 2 or 7 with phenyl hydrazine or hydrazine hydrate and 6 with only anhydrous hydrazine lead to derivatives of pyrazolo[3,4- d]-pyridazinone 8 and pyrazolo[3,4- d]pyridazine amine 9, respectivel. The reaction of 2 with 2-hydrazinopyri-dine provided hydrazono-pyrazole acid derivative 10, which was decarboxylated to give hydrazono-pyra-zole derivative 11. Pyrazolo[4,3- d]oxazinone 12 and 2-quinolyl pyrazolo[3,4- d]pyridazine 13 derivatives were also prepared by cyclocondensation reactions of 2 with hydroxylamine hydrochloride and 7 with acetaldehyde, respectively. [source]


    Quinoxalines X,. a new and convenient synthesis of 1H -Pyrazolo [3,4- b] quinoxalines (Flavazoles)

    JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 4 2001
    Gerhard Sarodnick
    Dedicated to Professor Gerhard Kempter on the occasion of his 70th birthday Quinoxaline-2-aldoximes and -ketoximes (6) react with hydrazine, alkylhydrazines or arylhydrazines under acidic conditions to afford lH -pyrazolo[3,4- b]quinoxalines (flavazoles) (1). Since the oximes (6) are easily available from phenylenediamine, the herein described methodology provides a convenient two step entry to various functionalized flavazoles. Furthermore, acylation and alkylation of the 1-unsubstituted lH -pyrazolo[3,4- b]quinoxalines 7 proceeds smoothly and in good yield to afford 31 different flavazoles 11 and 12. [source]


    Facile Synthesis and In-Vitro Antitumor Activity of Some Pyrazolo[3,4- b]pyridines and Pyrazolo[1,5- a]pyrimidines Linked to a Thiazolo[3,2- a]benzimidazole Moiety

    ARCHIV DER PHARMAZIE, Issue 1 2010
    Hatem A. Abdel-Aziz
    Abstract The key precursor E -3-(N,N -dimethylamino)-1-(3-methylthiazolo[3,2- a]benzimidazol-2-yl)prop-2-en-1-one 4 was synthesized in good yield using Gold's reagent. The reaction of enaminone 4 with 5-amino-3-aryl-1 - phenylpyrazoles 5a, b in refluxing acetic acid in the presence of sulphuric acid, yielded pyrazolo[3,4- b]pyridines 7a, b. Similarly, pyrazolo[1,5- a]pyrimidines 10a, b and 14a,f were prepared by reaction of enaminone 4 with 5-amino-1H -pyrazoles 8a, b and 12a,f, respectively. The structure of pyrazolo[1,5- a]pyrimidine 10b was determined by X-ray diffraction. The synthesized compounds were tested for their in-vitro antitumor activity against the colon cancer cell line CaCo-2; their cytotoxicity against the normal fibroblast cell line BHK was explored as well. Some of the tested compounds exhibited cell growth inhibitory activity. The significant antitumor activity of compound 14f against the CaCo-2 cell line (IC50 = 0.5 ,g/mL) was coupled with a lower toxicity against BHK (IC50 = 2.3 ,g/mL). [source]


    Pyrazolo[3,4- d]pyrimidine Derivatives as COX-2 Selective Inhibitors: Synthesis and Molecular Modelling Studies

    ARCHIV DER PHARMAZIE, Issue 6 2009
    Demetrio Raffa
    Abstract The pyrazolo[3,4- d]pyrimidine system shows a multitude of interesting pharmacological properties. Owing to the potential anti-inflammatory activity of 5-benzamido-pyrazolo[3,4- d]pyrimidin-4-one derivatives and considering the easy synthesis of this class of compounds, a set of new 5-benzamido-1H -pyrazolo[3,4- d]pyrimidin-4-ones has been prepared in 42-80% yields by reacting 5-aminopyrazole-4(N -benzoyl)carbohydrazide derivatives and the opportune triethylorthoesters. Compounds 8a, b, 10a,d, and 11a, b revealed a superior inhibitory profile against COX-2, when compared to that of reference standards NS398 and indomethacin. Molecular modelling studies confirmed the obtained biological results. [source]


    Synthesis and Biological Evaluation of Novel Pyrazoles and Pyrazolo[3,4- d]pyrimidines Incorporating a Benzenesulfonamide Moiety

    ARCHIV DER PHARMAZIE, Issue 4 2009
    Hayam M. A. Ashour
    Abstract Synthesis and biological evaluation of novel pyrazoles and pyrazolo[3,4- d]pyrimidines are reported. Fourteen compounds were selected by the NCI and tested for their preliminary in-vitro anticancer activity, whereas all the synthesized compounds were evaluated for their in-vitro antimicrobial activity. Compound 12a was proven to possess the highest anticancer activity with a broad spectrum profile. It showed particular effectiveness towards leukemia HL-60 (TB), K-562, non-small cell lung cancer NCI-H23, and colon cancer HT 29, KM 12 cell lines (GI50 = 6.59, 4.44, 1.37, 3.33, and 9.63 ,M, respectively). Out of the synthesized compounds, thirteen derivatives were found to display pronounced antimicrobial activity especially against P. aeruginosa. Compounds 2c, 5b, 10, 11b, 17b, 18b, and 19 were proven to be the most active with a broad spectrum of activity. Compound 19 was found to be equipotent to ampicillin against B. subtilis, whereas compounds 11b and 19 were four times superior to ampicillin against P. aeruginosa, while compounds 5b and 18b were equipotent to ampicillin against the same organism. Moreover, compounds 2c, 10, and 11b were nearly equipotent to ampicillin against E. coli. On the other hand, compounds 2c, 5b, 10, 11a, 17b, and 18b exerted nearly half the activity of clotrimazole against C. albicans. [source]


    ChemInform Abstract: Green Approach to the Synthesis of Polyfunctionalized Pyrazolo[4,,3,:5,6]pyrido[2,3-d]pyrimidines via Microwave-Assisted Multicomponent Reactions in Water Without Catalyst.

    CHEMINFORM, Issue 26 2010
    Feng Shi
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


    ChemInform Abstract: Molecular Iodine Promoted Synthesis of New Pyrazolo[3,4-d]pyrimidine Derivatives as Potential Antibacterial Agents.

    CHEMINFORM, Issue 23 2010
    Mehdi Bakavoli
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


    ChemInform Abstract: Preparation of 2,4,5-Trisubstituted Pyrazolo[4,3-c]quinolin-3-ones.

    CHEMINFORM, Issue 21 2010
    Douglas C. Beshore
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


    ChemInform Abstract: Recyclization of 1H-Pyrrole-2,3-diones into Pyrazolo[1,5-a]pyrimidines by the Action of Aminopyrazole.

    CHEMINFORM, Issue 20 2010
    E. S. Denislamova
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


    ChemInform Abstract: Microwave-Assisted Synthesis of Pyrazolo[4,3-f]quinolin-7-one Derivatives via Multi-Component Reactions.

    CHEMINFORM, Issue 5 2010
    Juhua Peng
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


    ChemInform Abstract: A New Synthesis of 2,8-Disubstituted Pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidines.

    CHEMINFORM, Issue 3 2010
    Anton V. Dolzhenko
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


    ChemInform Abstract: Synthesis of Fully Substituted Pyrazolo[3,4-b]pyridine-5-carboxamide Derivatives via a One-Pot Four-Component Reaction.

    CHEMINFORM, Issue 39 2009
    Ahmad Shaabani
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


    ChemInform Abstract: Vilsmeier,Haack Formylation of Acetonitrile Revisited: Synthesis of Novel Pyrazolo[1,5-a]pyrimidines and Triazolo[1,5-a]pyrimidine.

    CHEMINFORM, Issue 37 2009
    Maruti G. Ghagare
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


    ChemInform Abstract: An Efficient Single Step Synthesis of Pyridazine, Pyrazolo[5,1-c]-1,2,4-triazine, 1,2,4-Triazolo[5,1-c]-1,2,4-triazine and 1,2,4-Triazino[4,3-a]benzimidazole Derivatives.

    CHEMINFORM, Issue 29 2009
    Mohamed R. Shaaban
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


    ChemInform Abstract: Diversity-Oriented Synthesis of Substituted Pyrazolo[4,3-d][1,2,3]triazin-4-ones.

    CHEMINFORM, Issue 23 2009
    Daniel Meibom
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


    ChemInform Abstract: Synthesis and Tautomeric Structure of 6-Arylhydrazono 1H-Pyrazolo[3,,4,:4,5]pyrimido[1,6-b][1,2,4]triazepines (V).

    CHEMINFORM, Issue 22 2009
    Ahmad S. Shawali
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


    ChemInform Abstract: A New Strategy for the Synthesis of Pyrazolo[4,3-e][1,2,4]triazolo[4,3-c]pyrimidines and Pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidines.

    CHEMINFORM, Issue 11 2009
    Ahmad Sami Shawali
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


    ChemInform Abstract: Molecular Design of Pyrazolo[3,4-d]pyridazines.

    CHEMINFORM, Issue 9 2009
    V. S. Matiichuk
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


    ChemInform Abstract: Synthesis of Novel Pyrazolo[5,1-b]benzothiazoles: A New Pericyclic Pathway.

    CHEMINFORM, Issue 50 2008
    Betuel Tekiner-Gulbas
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


    ChemInform Abstract: Synthesis of Pyrazolo[3,4-b]pyridines Using Ammonium Acetate as Green Reagent in Multi-Component Reactions.

    CHEMINFORM, Issue 47 2008
    Madhukar N. Jachak
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


    ChemInform Abstract: An Unexpected Reaction of Cyanothioacetamide: Novel Preparation of Pyrazolo[3,4-b]pyridine Derivatives under MWI.

    CHEMINFORM, Issue 46 2008
    Xue Sen Fan
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


    ChemInform Abstract: Synthesis and Antimicrobial Activity of Some New Pyrazolo[3,4-d]pyrimidines (IV) and Thiazolo[4,5-d]pyrimidines (VI).

    CHEMINFORM, Issue 30 2008
    J. D. Akbari
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


    ChemInform Abstract: A Novel Synthesis of Pyrazolo[3,4-b]pyridine Derivatives Through Multicomponent Reaction in Ionic Liquid.

    CHEMINFORM, Issue 26 2008
    Xin Ying Zhang
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


    ChemInform Abstract: Concise Routes to Pyrazolo[1,5-a]pyridin-3-yl Pyridazin-3-ones

    CHEMINFORM, Issue 23 2008
    Karen A. Johnston
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


    ChemInform Abstract: An Efficient Synthesis of New Class of Pyrazolo[3,4-b]pyridine-6-one Derivatives by a Novel Cascade Reaction.

    CHEMINFORM, Issue 4 2008
    Feng Shi
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]