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1.
Sibel Alkan Bülent Zeybek Alev Doğan Rahmi Kasımoğulları Yunus Erdoğan Esma Kılıç 《Monatshefte für Chemie / Chemical Monthly》2009,140(4):381-386
Abstract Stoichiometric ionization constants of some pyrazole carboxylic acids [4-benzoyl-1-(3-nitrophenyl)-5-phenyl-1H-pyrazole-3-carboxylic
acid, 4-benzoyl-1-(4-nitrophenyl)-5-phenyl-1H-pyrazole-3-carboxylic acid, 4-(ethoxycarbonyl)-1,5-diphenyl-1H-pyrazole-3-carboxylic
acid, 4-(ethoxycarbonyl)-1-(3-nitrophenyl)-5-phenyl-1H-pyrazole-3-carboxylic acid, 4-(ethoxycarbonyl)-1-(4-nitrophenyl)-5-phenyl-1H-pyrazole-3-carboxylic
acid] were determined in ethanol–water mixtures of 50, 60, 70% ethanol (v/v) by a potentiometric titration method. Titrations
were performed in an ionic strength of 0.10 M NaCl at 25.0 ± 0.1 °C using an Orion 960 automatic titrator under a nitrogen
atmosphere. Using the potentiometric titration data, ionization constants were calculated in three different ways. The effects
of structure and solvent on the acidity of pyrazole carboxylic acids are also discussed.
Graphical abstract
相似文献
2.
A. Sener R. Kasimogullari M. K. Sener H. Genc 《Chemistry of Heterocyclic Compounds》2004,40(8):1039-1046
4-Benzoyl-1-(4-nitrophenyl)-5-phenyl-1H-pyrazole-3-carboxylic acid, obtained from the corresponding furan-2,3-dione and N-benzylidene-N'-(4-nitrophenyl)hydrazine, was converted via reactions of its acid chloride with various alcohols or N-nucleophiles into the corresponding ester or amide derivatives. The nitrile of the starting acid and 1-(4-aminophenyl)-4-benzoyl-5-phenyl-1H-pyrazole-3-carboxylic acid were also obtained. While cyclocondensation reactions of the two acids and the nitrile mentioned with hydrazines lead to pyrazolo[3,4-d]pyridazine derivatives, the reaction of starting acid with 2-hydrazinopyridine provided the hydrazonopyrazole acid derivative. 相似文献
3.
以3-( 4-氟苯基) -1H-吡唑-5-甲酸乙酯为原料,与H2NNH2?H2O发生肼解生成3-( 4-氟苯基) -1H-吡唑-5-甲酰肼,再与CS2环化生成2-巯基噁二唑中间体,最后在巯基上进行烷基化反应合成了一系列新型的2-硫醚-5-吡唑基-1,3,4-噁二唑类化合物,并利用IR、1H NMR、HRMS等波谱技术对目标化合物结构进行了表征。该合成方法具有原料易得,后处理简便,收率较高的优点。 相似文献
4.
Semenova A. M. Oganesyan R. V. Dotsenko V. V. Chigorina E. A. Aksenov N. A. Aksenova I. V. Netrebae E. E. 《Russian Journal of General Chemistry》2019,89(1):19-24
Russian Journal of General Chemistry - The reaction of 5-amino-3-(cyanomethyl)-1H-pyrazole-4-carbonitrile with 3-aryl-5-hydroxy-5- methyl-2,4-di(ethoxycarbonyl)cyclohexanones in acetic acid... 相似文献
5.
S. G. Mikhalenok N. M. Kuz'menok A. M. Zvonok 《Chemistry of Heterocyclic Compounds》2005,41(8):977-986
It was established that, in addition to ethyl 4-aryl-3-(2,3-epoxyalkanoyl)-4,5-dihydro-1H-pyrazole-5-carboxylates, the reaction
of diazoacetic ester with β-arylacryloyloxiranes also gives ethyl 4-aryl-3(5)-(3-hydroxy-2-methylalkanoyl)-1H-pyrazole-5(3)-carboxylates.
The latter are formed from the tautomeric ethyl 4-aryl-5-(2,3-epoxyalkanoyl)-4,5-dihydro-1H-pyrazole-3-carboxylates as a result
of intramolecular oxidative-reductive disproportionation.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, 1150–1160, August, 2005. 相似文献
6.
1-(取代吡唑-4-甲酰基)吡唑类化合物的合成及生物活性研究 总被引:4,自引:0,他引:4
设计合成了25个新型1-取代吡唑甲酰基吡唑系列衍生物,化合物结构经1HNMR、元素分析、IR和MS确证.生物活性测试结果表明,该类化合物具有一定除草活性,讨论了其结构与活性的关系. 相似文献
7.
A simple, novel, and efficient route for the synthesis of 5-amino-3-aryl-1-(tert-butyl)-1H-pyrazole-4-carboxamides 1 has been devised. Preparation of pyrazole bromide 3 from potassium tricyanomethanide can be accomplished in only two steps in good yield and features a selective Sandmeyer reaction on the corresponding diaminopyrazole. This allows for a more versatile synthesis of 5-amino-3-aryl-1-(tert-butyl)-1H-pyrazole-4-carboxamides 1 than was previously possible. 相似文献
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Mandal TN Roy S Konar S Jana A Das K Ray S Gupta S Saha R El Fallah MS Tercero J Butcher RJ Chatterjee S Kar SK 《Dalton transactions (Cambridge, England : 2003)》2012,41(2):413-423
The ditopic ligand PyPzOAPz (N-[(Z)-amino(pyrazin-2-yl)methylidene]-5-methyl-1-(pyridin-2-yl)-1H-pyrazole-3-carbohydrazonic acid) was synthesized by in situ condensation of methyl imino pyrazine-2-carboxylate with 5-methyl-1-(2-pyridyl) pyrazole-3-carbohydrazide. In this work we have also used two of our earlier ligands PzCAP (5-methyl-N-[(1E)-1-(pyridin-2-yl)ethylidene]-1H-pyrazole-3-carbohydrazonic acid) (Dalton Trans., 2009, 8215) and PzOAP (N-[(Z)-amino(pyridin-2-yl)methylidene]-5-methyl-1H-pyrazole-3-carbohydrazonic acid) (Dalton Trans., 2007, 1229). These ligands PzCAP, PzOAP and PyPzOAPz were made to react with Mn(ClO(4))(2)·6H(2)O to produce three pentanuclear Mn(II) clusters [Mn(5)(PzCAP)(6)](ClO(4))(4) (1), [Mn(5)(PzOAP)(6)](ClO(4))(4) (2) and [Mn(5)(PyPzOAPz)(6)](ClO(4))(4) (3). These complexes have been characterized by X-ray structural analyses and variable temperature magnetic susceptibility measurements. All complexes have a pentanuclear core with trigonal bipyramidal arrangement of Mn(II) atoms, where, the axial metal centers have a N(3)O(3) chromophore and the equatorial centers have N(4)O(2) with an octahedral arrangement. These Mn(5)(II) clusters 1, 2 and 3 show the presence of antiferromagnetic coupling within the pentanuclear manganese(II) core (J = -2.95, -3.19 and -3.00 cm(-1) respectively). Density functional theory calculations and continuous shape measurement (CShM) studies have been performed on these complexes to provide a qualitative theoretical interpretation of the antiferromagnetic behaviour shown by them. The pentanuclear Mn(II) cluster (1) on reaction with Cu(NO(3))(2)·6H(2)O in 1:1 mole proportion in CH(3)OH:H(2)O (60?:?40) forms a homoleptic [2 × 2] tetranuclear Cu(4)(II) grid [Cu(4)(PzCAP)(4)(NO(3))(2)](NO(3))(2)·8H(2)O (4). The same Cu(4)(II) grid is also obtained from a direct reaction between the ditopic ligand PzCAP with Cu(NO(3))(2)·6H(2)O in 1:1 mole proportion. This conversion of a cluster to a grid is a novel observation. 相似文献
10.
Da Qiang Zhang Gao Fei Xu Zhi Jin Fan Dao Quan Wang Xin Ling Yang De Kai Yuan 《中国化学快报》2012,23(6):669-672
In order to investigate the biological activity of novel bis-pyrazole compounds,a series of N-(3-alkyl-5-(N-methylcarbamyl)- 1H-pyrazol-4-yl)-3-alkyl-4-substituted-1H-pyrazole-5-carboxamides were designed and synthesized with ethyl 3-alkyl-1H-pyrazole -5-carboxylate 1 as starting materials.N-Methyl-3-alkyl-4-amino-1H-pyrazole-5-carboxamides 6 were obtained from 1 via 5 steps.3-Alkyl-4-substitued-1H-pyrazole-5-carboxyl chlorides 4a,4b,11a,11b,11c or 12 were also obtained from 1 via several steps.Target compounds 7a-7g were obtained after the reaction of 6 with the above 1H-pyrazole-5-carboxyl chlorides.Preliminary bioassay showed some compounds possessing good inactivation effect against TMV(tobacco mosaic virus).Compound 7a showed higher activity superior to ningnanmycin at a concentration of 5.0×10-4 g/mL and equal activity at 1.0×10-4 g/mL;7b and 7c showed equal activity to virazole both at concentrations of 5.0×10-4 g/mL and 1.0×10-4 g/mL. 相似文献
11.
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. 相似文献
12.
Introduction Pyrazole and its derivatives represent one of the most active classes of compounds possessing a wide spectrum of biological activities. During the past years, considerable evidence has been accumulated to demon-strate the efficacy of pyrazole derivatives including an-tibacterial,1 antifungal,2 herbicidal,3 insecticidal4 and other biological activities.5-7 Up to now, a great variety of these kind of compounds have been synthesized, among which some commercially pesticides have been… 相似文献
13.
将5-取代吡唑-3-甲酸乙酯1位甲基化,经水解反应得到3种中间体1-甲基-5-取代1H-吡唑-3-甲酸(2a~2c);以不同取代的羧酸为原料经一系列反应合成6种中间体3-取代4-氨基-5-巯基-1,2,4-均三唑(3a~3f);将中间体(2a~2c)和(3a~3f)在三氯氧磷条件下反应,合成出18种1,2,4-三唑并[3,4-b]-1,3,4-噻二唑类化合物(4a~4r),均未见文献报道。 通过IR、1H NMR、13C NMR和元素分析表征了化合物结构。 初步的生物活性测试结果显示,所合成的化合物均表现出不同程度的生长素活性和抑菌活性。 并选取抑菌活性较好的两个化合物进行抗菌药物最低抑菌浓度(MIC)的测定。 相似文献
14.
采用"一锅法"合成3-(4-甲氧基苯基)-1H-5-吡唑甲酸乙酯,分别将吡唑环上1-位甲基化、4-位氯代后水解,得到2种吡唑羧酸;以取代羧酸和氨基硫脲为原料,三氯氧磷为脱水剂,合成6种5-取代-2-氨基-1,3,4-噻二唑化合物;再将吡唑结构单元及1,3,4-噻二唑结构单元以酰胺键结合在一起,合成了12种新的酰胺化合物,目标产物最终收率可达50%以上。用元素分析、IR和1HNMR测试技术确定了其结构。用小麦芽鞘法测试其生长素活性均不高,有的对小麦芽鞘生长显示抑制作用。 相似文献
15.
Tobiishi S Sasada T Nojiri Y Yamamoto F Mukai T Ishiwata K Maeda M 《Chemical & pharmaceutical bulletin》2007,55(8):1213-1217
Methoxy and fluorine analogs substituted on the terminal carbon of the pentyl chain of N-(piperidinyl)-1-(2,4-dichlorophenyl)-4-methyl-5-(4-pentylphenyl)-1H-pyrazole-3-carboxamide (O-1302) were synthesized in a multi-step process from 5-phenyl-1-pentanol, which was based on the 1,5-diarylpyrazole core template of N-(piperidinyl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide (SR141716) through condensation of the respective amine with pyrazole carboxylic acid, in order to develop tracers for medical imaging. Their potency for inhibiting the binding of the CB1 antagonist [(3)H]SR141716 was evaluated with the aim of developing positron emission tomography (PET) ligands for the cerebral cannabinoid CB1 receptor. These analogs bearing a piperidinyl carboxamide at the C(3) of the pyrazole ring exhibited affinities comparable to those of the CB1 reference antagonist SR141716, which warrants further investigation using the radiolabeled form for biological imaging studies. A morpholine ring substituted at the C(3) of the pyrazole ring resulted in a reduction of the CB1 affinity. 相似文献
16.
Chaban T. I. Matiichuk Y. E. Matiychuk V. S. 《Russian Journal of General Chemistry》2020,90(7):1357-1361
Russian Journal of General Chemistry - A series of ethyl 4-[(Z)-(4-oxo-2-thioxo-1,3-thiazolidin-5-ylidene)methyl]-1-aryl-1H-pyrazole-3-carboxylates was obtained as a result of the reaction of ethyl... 相似文献
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A general protocol has been developed for the facile construction of titled derivatives via three component reaction between 3-substituted phenyl-1H-pyrazole-4-carbaldehyde, malononitrile and various Michael donors in presence of 5 mol% polystyrene supported 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene(PS-TBD). PS-TBD was reused for at least five runs with nearly constant catalytic activity. All compounds were screened for antimicrobial and antioxidant activities. 相似文献
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C(α),N-Carboalkoxyhydrazones were dilithiated with excess lithium diisopropylamide, condensed with succinic or glutaric acid anhydride, and cyclized to 1H-pyrazole-5-propanoic or 1H-pyrazole-5-butanoic acids. 相似文献