2749-59-9Relevant academic research and scientific papers
Preparative, mechanistic and tautomeric investigation of 1-phenyl and 1-methyl derivative of 3-methyl-5-pyrazolone
Fakhraian, Hossein,Nafari, Yaser
, (2021)
1-Phenyl and 1-methyl derivative of 3-methyl-5-pyrazolone were prepared quantitatively via a scalable solvent-free reaction of corresponding hydrazine derivative with ethyl acetoacetate. Different mechanisms have been proposed for the reaction of hydrazine derivatives (methyl or phenyl) with ethyl acetoacetate and also the tautomeric aspects of the targeted compounds have been discussed. Graphical abstract: [Figure not available: see fulltext.] Synopsis: 13C NMR and quantitative proportional amount of different tautomeric forms of 1,3-dimethyl-5-pyrazolone in DMSO-d6.
High chemoselectivity of C=S dipolarophile in 1,3-dipolar cycloaddition of nitrilimines and 1,2,4-triazepin-5-one derivatives: Experimental, theoretical and X-ray study
Azzouzi, Saida,El Messaoudi, Malika,Esseffar, M'hamed,Jalal, Rachid,Cano, Felix H.,Del Carmen Apreda-Rojas, Maria,Domingo, Luis R.
, p. 522 - 528 (2005)
Substituted 2,7-dimethyl-3-thioxo-3,4,5,6-tetrahydro-2H-[1,2,4]triazepin-5- one reacts as a dipolarophile with several N-aryl-C-ethoxycarbonylnitrilimines, in equimolar quantities, to give, in all cases, two types of products: diethyl 3-(p-aryl)-2-[N′-(p-aryl)-N′-(2′,7′-dimethyl-5′- oxo-5′,6′-dihydro-2H-[1,2,4]triazepin-3′-yl)-hydrazino]-2, 3-dihydro[1,3,4]thiadiazole-2,5-dicarboxylate (3a-3c in 20-25% yield) and ethyl 4-(p-aryl)-5-imino-1,4-dihydro[1,3,4]thiadiazole carboxylate (4a-4c in 45-50% yield). When 1:2 stoichiometry was used, the formation of product 3 (50%) was favoured. The reaction is entirely chemo- and regioselective. The structures of the compounds obtained, where aryl stands for p-chloro-phenyl (3b) in the first type and for tolyl (4a) in the second type, were determined by X-ray crystallography and analysed by spectral methods (NMR and mass spectroscopy). The global and local electrophilicity/nucleophilicity have been analysed to rationalize the chemical reactivity of the reactants. Copyright
Zeolite 4A supported CdS/g-C3N4 type-II heterojunction: A novel visible-light-active ternary nanocomposite for potential photocatalytic degradation of cefoperazone
AttariKhasraghi, Naime,Behnajady, Mohammad A.,Mehrizad, Ali,Modirshahla, Nasser,Zare, Karim
, (2021/09/15)
The CdS/g-C3N4 heterojunction photocatalyst supported on 4A zeolite was successfully synthesized using a simple chemical precipitation method. The physicochemical characteristics of the as-prepared ternary composite were assessed using X-Ray diffraction (XRD), field emission- scanning electron microscopy (FE-SEM), energy dispersive X-Ray (EDX), transmission electron microscopy (TEM), N2 adsorption–desorption, differential reflectance spectroscopy (UV–Vis-DRS), and photoluminescence (PL) techniques. The results confirmed the successful synthesis of the CdS/g-C3N4/4AZ nanocomposite and introduction of the CdS and g-C3N4 on the substrate of 4A zeolite. Cefoperazone (CFP) antibiotic was tested as the model pollutant to assess the photocatalytic performance of the synthesized nanocomposite under visible light irradiation. The response surface methodology (RSM) and artificial neural network (ANN) showed desirable reasonability for the prediction of the CFP degradation efficiency. More than 93% of CFP with a concentration of 17 mg L-1 degraded in the presence of the 0.4 g L-1 of the catalyst at pH of 9 after 80 min treatment time (RSM-based optimization results). The pH of the solution, irradiation time, catalyst dosage, and the initial concentration of the CFP affected degradation efficiency with a percentage impact of 37, 29, 19, and 15 %, respectively (ANN-based modeling results). The addition of 1 mM of isopropanol, benzoquinone, and sodium oxalate reduced the CFP degradation efficiency from 93.23% to 85.18, 41.16, and 32.47%, respectively, proving the decisive role of the °O2– and h+ in the photodegradation process. The kinetic studies indicated the following of the process from the Langmuir-Hinshelwood's pseudo-first-order model (kapp = 3.71 × 10-2 min?1). The structure of the identified by-products using GC-MS analysis confirmed that CFP mainly decomposed through the cleavage of C-S, C-N, and N-N bonds. Moreover, the formation of the aliphatic compounds and carboxylic acids as by-products confirmed nearly complete mineralization of the CFP to non-toxic products.
Expedient discovery for novel antifungal leads targeting succinate dehydrogenase: Pyrazole-4-formylhydrazide derivatives bearing a diphenyl ether fragment
Chen, Min,Li, Guohua,Lu, Aimin,Qiu, Lingling,Wang, An,Wang, Xiaobin,Xue, Wei,Yang, Chunlong
, p. 14426 - 14437 (2020/12/22)
The pyrazole-4-carboxamide scaffold containing a flexible amide chain has emerged as the molecular skeleton of highly efficient agricultural fungicides targeting succinate dehydrogenase (SDH). Based on the above vital structural features of succinate dehydrogenase inhibitors (SDHI), three types of novel pyrazole-4-formylhydrazine derivatives bearing a diphenyl ether moiety were rationally conceived under the guidance of a virtual docking comparison between bioactive molecules and SDH. Consistent with the virtual verification results of a molecular docking comparison, the in vitro antifungal bioassays indicated that the skeleton structure of title compounds should be optimized as an N′-(4-phenoxyphenyl)-1H-pyrazole-4-carbohydrazide scaffold. Strikingly, N′-(4-phenoxyphenyl)-1H-pyrazole-4-carbohydrazide derivatives 11o against Rhizoctonia solani, 11m against Fusarium graminearum, and 11g against Botrytis cinerea exhibited excellent antifungal effects, with corresponding EC50 values of 0.14, 0.27, and 0.52 μg/mL, which were obviously better than carbendazim against R. solani (0.34 μg/mL) and F. graminearum (0.57 μg/mL) as well as penthiopyrad against B. cinerea (0.83 μg/mL). The relative studies on an in vivo bioassay against R. solani, bioactive evaluation against SDH, and molecular docking were further explored to ascertain the practical value of compound 11o as a potential fungicide targeting SDH. The present work provided a non-negligible complement for the structural optimization of antifungal leads targeting SDH.
Metal-Free Direct C–H Thiolation and Thiocyanation of Pyrazolones
Kittikool, Tanakorn,Yotphan, Sirilata
supporting information, (2020/02/13)
Metal-free approach for direct C–H thiolation and thiocyanation of N-substituted pyrazolones with disulfides and thiocyanate salts, respectively, are developed. These reactions allow the C–S bond coupling to proceed effectively under mild conditions, providing useful and convenient methods for preparation of a series of 4-thio-substituted pyrazolone analogues, which have potential applications in organic, medicinal and material chemistry. Preliminary mechanistic investigation suggested that radical processes are likely to involve in these transformations.
Method for synthesizing 1,3-dimethyl-1H-pyrazole-4-carboxylic acid
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Paragraph 0016; 0035; 0036; 0043-0048, (2019/11/12)
The invention relates to a method for synthesizing 1,3-dimethyl-1H-pyrazole-4-carboxylic acid. The method comprises the step that 1,3-dimethyl-1H-pyrazole-4-carboxylic acid is prepared from the raw material: ethyl acetoacetate through condensation and ring closure, formylation, reductive dechlorination and oxidation. Compared with an existing method, the method has lower reaction cost, a higher yield and better economic performance; and the problems such as cost and environmental pollution caused by heavy metal oxidation are solved, and conditions are created for industrialization.
Novel 5-chloro-pyrazole derivatives containing a phenylhydrazone moiety as potent antifungal agents: synthesis, crystal structure, biological evaluation and a 3D-QSAR study
Jiao, Jian,Wang, An,Chen, Min,Wang, Meng-Qi,Yang, Chun-Long
, p. 6350 - 6360 (2019/04/25)
Based on the active substructure combination principle, twenty-four novel 5-chloro-pyrazole derivatives containing a phenylhydrazone moiety were designed, synthesized, and evaluated for their antifungal activity. Their structures were confirmed using 1H NMR, 13C NMR, and HR-MS spectra. The single-crystal structure of compound 8a was analyzed emphatically using X-ray diffraction. The antifungal activities against Fusarium graminearum, Botrytis cinerea, and Rhizoctonia solani were evaluated in vitro. The results of the bioassays revealed that most of the target compounds showed obvious fungicidal activity. Strikingly, the compound 7c exhibited the most potent activity with EC50 values of 0.74, 0.68, and 0.85 μg mL?1 against the above three plant pathogenic fungi, respectively. The compounds 7c, 8d, and 8g showed significant bioactivity against R. solani with EC50 values of 0.85, 0.25, and 0.96 μg mL?1, respectively. In addition, CoMFA and CoMSIA molecular modeling was performed for a 3D-QSAR study, and presented a good predictive ability with q2 values of 0.575 and 0.667, and r2 values of 0.961 and 0.962, respectively. The results provide useful information for guiding the design and synthesis of novel potent pyrazole derivatives with good antifungal activity.
Design of a simple and efficient synthesis for bioactive novel pyrazolyl-isoxazoline hybrids
Sankar, Balakrishnan,Harikrishnan, Muniyasamy,Raja, Ranganathan,Sadhasivam, Velu,Malini, Nelson,Murugesan, Sepperumal,Siva, Ayyanar
, p. 10458 - 10467 (2019/07/08)
A simple and new methodology has been developed for the synthesis of novel bioactive pyrazolyl-isoxazoline hybrids from a pyrazolyl-substituted oxime and various substituted allyloxybenzenes, which are easily available, inexpensive starting materials. All the novel synthesized target hybrids were characterized by NMR, IR, and mass spectroscopic techniques. We have employed some of the hybrid materials in anti-bacterial and anti-fungal activity studies. The hybrid materials 6m and 6p exhibited the best anti-bacterial and anti-fungal activities.
A new method for making pyrazole or pyrimidinone
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Paragraph 0306-0310, (2019/11/28)
The invention relates to the use of an amine compound in a method for producing a fluorinated or non-fluorinated 5- or 6-membered heterocyclic compound (preferably pyrazole or pyrimidinone) containingtwo nitrogen atoms in a ring system. The invention also relates to a method for producing a pyrazole or pyrimidinone, which may be fluorinated or may not be fluorinated (non-fluorinated). Each of thefluorinated pyrazole or fluorinated pyrimidinone is a very important structural unit for pharmaceutical and agricultural applications. For example, fungicides are strongly dependent on bifenapram, fluoxastrobin, flubenazolid, fluoxastrobin, pyraclostrobin, and pyracloprid, each with this fluorinated pyrazole as a key structural unit, and benflufenazole respectively, or diflufenacil and chlorfensulfazone (dimethachlor).
Excellent antitumor and antimetastatic activities based on novel coumarin/pyrazole oxime hybrids
Dai, Hong,Huang, Meiling,Qian, Jianqiang,Liu, Ji,Meng, Chi,Li, Yangyang,Ming, Guxu,Zhang, Ting,Wang, Senling,Shi, Yujun,Yao, Yong,Ge, Shushan,Zhang, Yanan,Ling, Yong
, p. 470 - 479 (2019/02/12)
A series of hybrids 10a-v based on coumarin/pyrazole oxime have been synthesized, and exhibit good to excellent antitumor activities. Compound 10n has shown remarkable anticancer effect on SMMC-7721 cells (IC50 = 2.08 μM), which is considerably lower than 5-FU (IC50 = 37.8 μM) and similar to ADM (IC50 = 2.67 μM), with little effect on normal hepatic cells LO2. Notably, the suppression experiments of metastatic activities reveal that 10n also displays significant anti-metastasis effects through inhibiting cell migration and invasion in highly metastatic SMMC-7721 cell line, and dose-dependently reverses TGF-β1-induced epithelial-mesenchymal transition (EMT) procedure better than ADM. Finally, 10n also possesses low acute toxicity and potent tumor growth inhibitory property against SMMC-7721 cell lines in vivo. Our findings suggest that novel coumarin/pyrazole oxime hybrids are promising therapeutic agent candidates for further research.
