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Pyrazole Derivative (pyrazole + derivative)
Selected AbstractsAntileishmanial and Antibacterial Activity of a New Pyrazole Derivative Designated 4-[2-(1-(Ethylamino)-2-methylpropyl)phenyl] -3-(4-methylphenyl)-1-phenylpyrazole (IV).CHEMINFORM, Issue 39 2006Zainaba Dardari 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, please click on HTML or PDF. [source] ChemInform Abstract: Synthesis of Tetrahetrocyclic Systems Including Pyrido[2,,3,:3,4]pyrazolo[1,5-a]pyrimidine Fused with Pyrazole Derivatives and Isolated with 1,3,4-Oxa-, Thiadiazole-, and 1,2,4-Tetrazole Derivatives.CHEMINFORM, Issue 34 2010Farag A. El-Essawy Abstract A series of fused and isolated tetracyclic heterocycles are synthesized by common methods. [source] Potassium 2-Cyanoethylene-1-thiolate Derivatives: A New Preparative Route to 2-Cyanoketene S,N-Acetals and Pyrazole DerivativesCHEMINFORM, Issue 7 2005Galal H. Elgemeie Abstract For Abstract see ChemInform Abstract in Full Text. [source] 2-Phenyl-2,3-dihydro-1H-imidazo[1,2-b]pyrazole Derivatives: New Potent Inhibitors of fMLP-Induced Neutrophil Chemotaxis.CHEMINFORM, Issue 43 2007Olga Bruno 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, please click on HTML or PDF. [source] Synthesis of 1,4-Dihydropyrano[2,3-c]pyrazole Derivatives.CHEMINFORM, Issue 51 2005T. N. Vasyun'kina Abstract For Abstract see ChemInform Abstract in Full Text. [source] Reactions of Di(tert -butyl)diazomethane with Acceptor-Substituted Ethylenes,HELVETICA CHIMICA ACTA, Issue 5 2007Rolf Huisgen Abstract Di(tert- butyl)diazomethane (4) is a nucleophilic 1,3-dipole with strong steric hindrance at one terminus. In its reaction with 2,3-bis(trifluoromethyl)fumaronitrile ((E)- BTE), a highly electrophilic tetra-acceptor-substituted ethene, an imino-substituted cyclopentene 9 is formed as a 1,:,2 product. The open-chain zwitterion 10, assumed as intermediate, adds the second molecule of (E)- BTE. The 19F- and 13C-NMR spectra allow the structural assignment of two diastereoisomers, 9A and 9B. The zwitterion 10 can also be intercepted by dimethyl 2,3-dicyanofumarate (11) and furnishes diastereoisomeric cyclopentenes 12A and 12B; an X-ray-analysis of 12B confirms the ,mixed' 1,:,1,:,1 product. Competing is an (E)- BTE -catalyzed decomposition of 4 to give 2,3,4,4-tetramethylpent-1-ene (7)+N2; the reaction of (E)- BTE with a trace of water appears to be responsible for the chain initiation. The H2SO4 -catalyzed decomposition of diazoalkane 4, indeed, produced the alkene 7 in high yield. The attack on the hindered diazoalkane 4 by 11 is slower than that by (E)- BTE; the zwitterionic intermediate 21 undergoes cyclization and furnishes the tetrasubstituted furan 22. In fumaronitrile, electrophilicity and steric demand are diminished, and a 1,3-cycloaddition produces the 4,5-dihydro-1H -pyrazole derivative 25. The reaction of 4 with dimethyl acetylenedicarboxylate leads to pyrazole 29+isobutene. [source] Correlation between the predicted and the observed biological activity of the symmetric and nonsymmetric cyclic urea derivatives used as HIV-1 protease inhibitors.JOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 3 2003A 3D-QSAR-CoMFA method for new antiviral drug design Abstract The predicted inhibition constant (Ki) and the predicted inhibitor concentration (IC90) of the HIV-1 protease (HIV-1 PR) inhibitors: symmetric and nonsymmetric - benzyl, ketone, oxime, pyrazole, imidazole, and triazole cyclic urea derivatives, were obtained by the 3D-CoMFA (Comparative Molecular Field Analysis) method. The CoMFA statistical parameters: cross-validate correlation coefficient (q2), higher than 0.5, and the fitted correlation coefficient (r2), higher than 0.90 validated the predicted biological activities. The best predictions were found for the trifluoromethyl ketoxime derivative (log 1/Ki predict = 8.42), the m-pyridineCH2 pyrazole derivative (log 1/Ki predict = 9.77) and the 1,2,3 triazole derivative (log 1/Ki predict = 7.03). We attempted to design a new potent HIV-1 protease inhibitor by addition of o-benzyl to the (p-HOPhCH2) pyrazole 12f derivative inhibitor. A favorable steric area surrounded the o-benzyl, suggesting a possible new potent HIV-1 protease inhibitor. [source] ,-Oxoanilides in heterocyclic synthesis: An expeditious synthesis of new polyfunctionally substituted pyridine and pyrazole derivativesJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 6 2008A. M. Hussein 3-Oxo- N -{4-[(pyrimidin-2-ylamino)sulfonyl]phenyl}butanamide 3 was condensed with (DMF-DMA) in refluxing dry dioxane to yield branched structure 4 not its linear isomeric 5. Compound 4 readily reacted with active methylene to yield compounds 8a-c, 14, 17 and 20 respectively. Also enaminone 4 reacted with phenyl hydrazine giving 24 and 25. In contrast, when compound 4 reacted with hydrazine hydrate in the same experimental conditions pyrazole derivative 27 was obtained. Furthermore, condensation of anilide 3 with triethylorthoformate in refluxing acetic anhydride afforded the ethoxy methylene derivative 28. On the other hand, compound 28 was reacted with active methylene reagents, and hydrazines to afford the products identical in all respects (mp., mixed mp., and spectral data) with those corresponding to compounds 6-27 respectively. Similarly, compound 3 was reacted with hydrazine hydrate to afford the reaction product 29. Also, compound 3 reacted with cyanoacetamide in refluxing ethanolic pipridine solution to yield the pyridine derivative 30. Finally, 3 reacted with hydroxylamine hydrochloride in refluxing ethanol/sodium acetate solution to yield the acyclic oxime derivative 31. [source] Synthesis and some reactions of 4-(ethoxycarbonyl)-1,5-diphenyl-1H -pyrazole-3-carboxylic acidJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 5 2007Ahmet, ener 1,5-Diphenyl-1H -pyrazole-3,4-dicarboxylic acid-4-ethyl ester 2, obtained from the 4-ethoxycarbonyl-5-phenyl-2,3-furandione 1 and N -benzylidene- N,-phenyl hydrazine, was converted via reactions of its acid chloride 3 with various alcohols or N-nucleophiles into the corresponding ester 5 or amide derivatives 6, respectively. In addition, 2 was decarboxylated to give ethyl 1,5-diphenylpyrazole-4-carboxylate 4. Nitrile 7 derivative of 2 was also obtained by dehydration of 6a in a mixture of SOCl2 and DMF. While cyclocondensation reaction of 2 with hydrazine hydrate leads to the formation of pyrazolo[3,4- d]pyridazine-4,7-dione 8, the reaction of 3 with anhydrous hydrazine provided a new bis pyrazole derivative 9. [source] 3-(1H -Pyrrol-2-yl)-1H -pyrazole forms an unusual hydrogen-bonded two-dimensional (3,4)-connected netACTA CRYSTALLOGRAPHICA SECTION C, Issue 10 2009Katie E. R. Marriott The title compound, C7H7N3, is the first crystallographically characterized 1H -pyrrolyl-1H -pyrazole derivative and contains two unique molecules in its asymmetric unit (Z, = 2). These molecules associate into centrosymmetric tetramers through N,H...N hydrogen bonding, including a cyclic dimerization of one of the two unique pyrazole rings. These tetramers are linked further by two weaker N,H..., contacts to give a novel two-dimensional (3,4)-connected net with a (32.8)2(3.82)2 topology. [source] ,-Oxoanilides in heterocyclic synthesis: An expeditious synthesis of new polyfunctionally substituted pyridine and pyrazole derivativesJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 6 2008A. M. Hussein 3-Oxo- N -{4-[(pyrimidin-2-ylamino)sulfonyl]phenyl}butanamide 3 was condensed with (DMF-DMA) in refluxing dry dioxane to yield branched structure 4 not its linear isomeric 5. Compound 4 readily reacted with active methylene to yield compounds 8a-c, 14, 17 and 20 respectively. Also enaminone 4 reacted with phenyl hydrazine giving 24 and 25. In contrast, when compound 4 reacted with hydrazine hydrate in the same experimental conditions pyrazole derivative 27 was obtained. Furthermore, condensation of anilide 3 with triethylorthoformate in refluxing acetic anhydride afforded the ethoxy methylene derivative 28. On the other hand, compound 28 was reacted with active methylene reagents, and hydrazines to afford the products identical in all respects (mp., mixed mp., and spectral data) with those corresponding to compounds 6-27 respectively. Similarly, compound 3 was reacted with hydrazine hydrate to afford the reaction product 29. Also, compound 3 reacted with cyanoacetamide in refluxing ethanolic pipridine solution to yield the pyridine derivative 30. Finally, 3 reacted with hydroxylamine hydrochloride in refluxing ethanol/sodium acetate solution to yield the acyclic oxime derivative 31. [source] Synthesis of functionalized compounds containing pyridazine and related moietiesJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 3 2005Jurij Svete 3-Aminopyridazines 17 and 3-hydrazinopyridazines 18 were used as building blocks for the preparation of various types of functionalized, pyridazine ring containing compounds. 3-Aminopyridazines were employed in the synthesis of 3-(6-chloroimidazo[1,2- b]pyridazin-2-yl)alanines 26, 27 and for the preparation of 3-amino-4H -pyrimido[1,2- b]pyridazin-4-ones 103, intermediates in the ,ring switching' synthesis of alkyl 1-pyridazin-3-yl-1,2,3-triazole-4-carboxylates 106. On the other hand, hydrazinopyridazines 18 were employed in a two-step preparation of 3-functionalized 1,2,4-triazolo[4,3- b]pyridazines via condensation with functionalized aldehydes and their enamino analogs followed by oxidative cyclization of the intermediate hydrazones. In this manner, 1,2,4-triazolo[4,3- b]pyridazin-3-yl substituted alanines 29, 30, polyols 33, 39,48, C -nucleosides 49, 50, and terpenes 58, 62, 64,69 were prepared. In another general approach, 3-hydrazinopyridazines 18 were treated with functionalized enaminones as 1,3-dielectrophiles to give the 1-(substituted pyridazin-3-yl)-1H -pyrazole derivatives containing an ester 72, 73, 75, 76, alanine 79, 84, 85, 87, 2-phenylethylamine 97, 99, and ,-amino alcohol functional element 98, 100. In the reaction of 4-oxohomoglutamate 82 with hydrazine hydrate and methyl hydrazine, chiral functionalized tetrahydropyridazinones 88a,b were obtained. [source] Supramolecular structure of 1H -pyrazoles in the solid state: a crystallographic and ab initio studyACTA CRYSTALLOGRAPHICA SECTION B, Issue 6 2000Concepción Foces-Foces The secondary structure of 1H -unsubstituted pyrazole derivatives bearing only one hydrogen donor group and one or more acceptor groups has been analyzed in terms of some descriptors representing the substituents at C3 and C5. The substituent at C4 appears to affect mainly the tertiary or quaternary structure of these compounds. The proposed semi-quantitative model, which explains most hydrogen-bonded motifs as a combination of the effects of substituents at C3 and C5, has also been examined as a function of the steric and polarizability effects of these substituents represented by molar refractivity. The model also applies to other five-membered rings (1,2,4-triazoles, 1,2,4-diazaphospholes and 1,2,4-diazaarsoles). Furthermore, ab initio calculations at RHF/6-31G* have been performed to discover the relative stability of three of the four hydrogen-bond patterns displayed by several symmetrical pyrazoles (dimers, trimers, tetramers). The fourth motif, catemers, has only been discussed geometrically. [source] Immunomodulatory and Anticancer Activities of Some Novel 2-Substituted-6-bromo-3-methylthiazolo[3,2- a]benzimidazole DerivativesARCHIV DER PHARMAZIE, Issue 4 2009Hatem A. Abdel-Aziz Abstract Ethyl 6-bromo-3-methyl-1,3-thiazolo[3,2- a]benzimidazole-2-carboxylate 2 was prepared by the ambient temperature bromination of ethyl 3-methyl-1,3-thiazolo[3,2- a]benzimidazole-2-carboxylate 1. The acid hydrazide 4 was obtained by the reaction of ester 2 with hydrazine hydrate. Treatment of compound 4 with benzaldehyde or 2-thiophenaldehyde yielded the corresponding hydrazones 6a and 6b, respectively, while the reaction of acid hydrazide 4 with ethoxymethylene malononitrile (7a) or with ethyl ethoxymethylene cyanoacetate (7b) in refluxing ethanol afforded pyrazole derivatives 9a and 9b, respectively. Taken together, from the biological investigations compounds 9a and 9b were the most significant inhibitors of LPS-stimulated NO generation from Raw murine macrophage 264.7, and, as another result, compounds 2 and 4 had a weak radical scavenging activity against DPPH radicals. Moreover, 2, 4, and 9a had a concomitant strong cytotoxicity against both colon carcinoma cells (HCT-116) and hepatocellular carcinoma cells (Hep-G2) while 9b showed specific cytotoxicity only against colon carcinoma cells. [source] Synthesis of some heteroaryl pyrazole derivatives and their biological activitiesCHINESE JOURNAL OF CHEMISTRY, Issue 4 2000Chen Han-Song Abstract In order to search for novel fungicides with high activity, a series of heteroaryl pyrazoles were synthesized from 5-pyrazole formhydrazide. The structures of all new compounds were confirmed by spectroscopic methods and microanalyses. Preliminary bioassays indicated that some compounds showed fungicidal activity against Puccinia tritinia and PGR activity as well. [source] | |||||||||||||||||||||||||