- Coupling ofN-tosylhydrazones with tetrazoles: synthesis of 2-β-d-glycopyranosylmethyl-5-substituted-2H-tetrazole type glycomimetics
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Coupling reactions ofO-peracylated 2,6-anhydro-aldose tosylhydrazones (C-(β-d-glycopyranosyl)formaldehyde tosylhydrazones) with tetrazoles were studied under metal-free conditions using thermic or microwave activation in the presence of different bases. The reactions proved highly regioselective and gave the corresponding, up-to-now unknown 2-β-d-glycopyranosylmethyl-2H-tetrazoles in 7-67% yields. The method can be applied to get new types of disaccharide mimetics, 5-glycosyl-2-glycopyranosylmethyl-2H-tetrazoles, as well. Galectin binding studies withC-(β-d-galactopyranosyl)formaldehyde tosylhydrazone and 2-(β-d-galactopyranosylmethyl)-5-phenyl-2H-tetrazole revealed no significant inhibition of any of these lectins.
- Kaszás, Tímea,Cservenyák, Ivett,Juhász-Tóth, éva,Kulcsár, Andrea E.,Granatino, Paola,Nilsson, Ulf J.,Somsák, László,Tóth, Marietta
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supporting information
p. 605 - 618
(2021/02/06)
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- A robust and recyclable ionic liquid-supported copper(II) catalyst for the synthesis of 5-substituted-1H-tetrazoles using microwave irradiation
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Abstract: A novel and robust ionic liquid-supported copper(II) catalyst has been developed and explored for the efficient synthesis of 5-substituted-1H-tetrazoles using microwave irradiation. The ionic liquid-supported catalyst facilitated the efficient isolation of tetrazole products with high purity by simple extraction with organic solvent. Recovered ionic liquid-supported copper(II) catalyst could be recycled for three times for the synthesis of tetrazole products with high purity. This synthetic protocol offers a very clean, convenient, and microwave-assisted environment-friendly method for the efficient synthesis of 5-substituted-1H-tetrazoles with high yield. Graphic abstract: [Figure not available: see fulltext.].
- Padmaja,Chanda, Kaushik
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p. 1307 - 1317
(2019/11/14)
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- Discovery of mercaptopropanamide-substituted aryl tetrazoles as new broad-spectrum metallo-β-lactamase inhibitors
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β-Lactam antibiotic resistance mediated by metallo-β-lactamases (MBL) has threatened global public health. There are currently no available inhibitors of MBLs for clinical use. We previously reported the ruthenium-catalyzed meta-selective C-H nitration synthesis method, leading to some meta-mercaptopropanamide substituted aryl tetrazoles as new potent MBL inhibitors. Here, we described the structure-activity relationship of meta- and ortho-mercaptopropanamide substituted aryl tetrazoles with clinically relevant MBLs. The resulting most potent compound 13a showed IC50 values of 0.044 μM, 0.396 μM and 0.71 μM against VIM-2, NDM-1 and IMP-1 MBL, respectively. Crystallographic analysis revealed that 13a chelated to active site zinc ions via the thiol group and interacted with the catalytically important residues Asn233 and Tyr67, providing further structural information for the development of thiol based MBL inhibitors. This journal is
- Yan, Yu-Hang,Chen, Jian,Zhan, Zhen,Yu, Zhu-Jun,Li, Gen,Guo, Li,Li, Guo-Bo,Wu, Yong,Zheng, Yongxiang
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p. 31377 - 31384
(2020/09/21)
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- [Cu(phen)(PPh3)2]NO3-catalyzed microwave-assisted green synthesis of 5-substituted 1H-tetrazoles
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Abstract: An efficient synthetic methodology for construction of 5-substituted 1H-tetrazoles under microwave irradiation in green medium is described. With [Cu(phen)(PPh3)2]NO3 as catalyst and H2O-isopropyl alcohol (IPA) as reaction medium, various substituted nitriles underwent (3?+?2) cycloaddition reaction with NaN3 under microwave irradiation to provide corresponding 5-substituted 1H-tetrazoles in high yield. This method is not only efficient and general but also benefits from high functional group tolerance. This environmentally friendly synthetic methodology is visualized as an alternative to existing procedures, providing a simple route to privileged scaffolds.
- Padmaja,Meena,Maiti, Barnali,Chanda, Kaushik
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p. 7365 - 7374
(2017/09/06)
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- Piperazinium dihydrogen sulfate: An acidic ionic liquid for the [3+2] cycloaddition reaction of sodium azide with organic nitriles
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Background: Tetrazoles are imperative nitrogen rich heterocyclic compounds with a wide range of applications in the field of organic synthesis, coordination chemistry, material sciences, and medicinal chemistry. A most common approach for the synthesis of 5-substituted-1H-Tetrazoles is achieved by [3+2] cycloaddition reaction of azides to nitriles. In this paper a new acidic ionic liquid is introduced as a catalyst to promote the mentioned reaction. Methods: Piperazinium dihydrogen sulfate:as a new acidic ionic compound was obtained by treatment of piperazine with sulfuric acid, which is further was applied as a catalyst for the [3+2] cycloaddition reaction of azides to organic nitriles. Results: The [3+2] cycloaddition reaction of sodium azide with structurally different organic nitriles using only 1.5 mol% of the piperazinium dihydrogen sulfate proceeded well at 100°C and 5-substituted-1H-Tetrazoles were prepared in good to excellent yields. Herein, piperazinium dihydrogen sulfate has a dual role of catalyst and reaction medium, which circumvents the use of any organic solvent. The catalyst is also recyclable. This method is particularly suitable for benzonitriles carrying deactivating groups which furnished the corresponding products in excellent yields. By this method, mono [3+2] cycloaddition product of dicyanides was obtained. Conclusion: In conclusion, piperazinium dihydrogen sulfate as a new acidic ionic compound was applied to promote synthesis of 5-substituted-1H-Tetrazoles through [3+2] cycloaddition reaction of organic nitriles with sodium azide. This new ionic compound can be easily separated from the reaction mixture which resulted to a simple work-up of the products.
- Nowrouzi, Najmeh,Farahi, Soghra,Irajzadeh, Maryam
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p. 113 - 119
(2016/02/27)
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- 4-(N,N-Dimethylamino)pyridinium acetate as a recyclable catalyst for the synthesis of 5-substituted-1H-tetrazoles
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An efficient method for the synthesis of 5-substituted-1H-tetrazoles through the reaction of nitriles with sodium azide using 4-(N,N-dimethylamino)pyridinium acetate as a recyclable catalyst with ionic liquid character is described. The reactions proceed well at 100 °C and provide the corresponding tetrazoles in good to excellent yields. This method has the advantage of easy work-up of the product without the requirement of HCl. Mono [3+2] cycloaddition products were obtained from dicyanides via this method.
- Nowrouzi, Najmeh,Farahi, Soghra,Irajzadeh, Maryam
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p. 739 - 742
(2015/01/30)
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- Mesoporous AlPO4: A highly efficient heterogeneous catalyst for synthesis of 5-substituted 1H-tetrazoles from nitriles and sodium azide via [3 + 2] cycloaddition
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The mesoporous AlPO4 with high surface area and fine mesoporous structure was prepared by a soft template method and showed excellent catalytic performance for synthesis of 5-substituted 1H-tetrazoles from various nitriles and sodium azide with
- Ai, Man,Lang, Leiming,Li, Baojun,Xu, Zheng
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supporting information; experimental part
p. 814 - 816
(2012/09/22)
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- Design of pentapeptidic BACE1 inhibitors with carboxylic acid bioisosteres at P1′ and P4 positions
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We previously reported potent BACE1 inhibitors KMI-420 and KMI-570 possessing a hydroxymethylcarbonyl isostere as a substrate transition-state mimic. Acidic moieties at the P1′ and P4 positions of KMI inhibitors are thought to be unfavorable in terms of membrane permeability across the blood-brain barrier. Herein, we replaced acidic moieties at the P4 position with hydrogen bond accepting groups and acidic moieties at the P1′ position with less acidic and similar molecular-size moieties (carboxylic acid or tetrazole bioisosteres). These inhibitors exhibited improved BACE1 inhibitory activities and a thorough quantitative structure-activity relationship study was performed.
- Tagad, Harichandra D.,Hamada, Yoshio,Nguyen, Jeffrey-Tri,Hamada, Takashi,Abdel-Rahman, Hamdy,Yamani, Abdellah,Nagamine, Ayaka,Ikari, Hayato,Igawa, Naoto,Hidaka, Koushi,Sohma, Youhei,Kimura, Tooru,Kiso, Yoshiaki
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experimental part
p. 3175 - 3186
(2010/07/04)
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- Practical synthesis of 5-substituted tetrazoles under microwave irradiation
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5-Substituted tetrazoles were prepared by treatment of nitriles with sodium azide and triethylammonium chloride in nitrobenzene in a microwave reactor. This practical method combines the advantages of previous procedures, including good-to-excellent yields, short reaction times, and easy isolation of the product. Moreover, sterically hindered tetrazoles, as well as those deactivated by electron-donating groups, can be prepared. Georg Thieme Verlag Stuttgart.
- Roh, Jaroslav,Artamonova, Tatjana V.,Vavrova, Katerina,Koldobskii, Grigorii I.,Hrabalek, Alexandr
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experimental part
p. 2175 - 2178
(2010/01/05)
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- Design, synthesis, and structure-activity relationships of novel insulin receptor tyrosine kinase activators
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A novel series of symmetrical ureas of [(7-amino(2-naphthyl))sulfonyl] phenylamines were designed, synthesized, and tested for their ability to increase glucose transport in mouse 3T3-L1 adipocytes, a surrogate readout for activation of the insulin receptor (IR) tyrosine kinase (IRTK). A structure-activity relationship was established that indicated glucose transport activity was dependent on the presence of two acidic functionalities, two sulfonamide linkages, and a central urea or 2-imidazolidinone core. Compound 30 was identified as a potent and selective IRTK activator. At low concentrations, 30 was able to increase the tyrosine phosphorylation of the IR stimulated by submaximal insulin. At higher concentrations, 30 was able to increase tyrosine the phosphorylation levels of the IR in the absence of insulin. When administered intraperitoneally (ip) and orally (po), 30 improved glucose tolerance in hypoinsulinemic, streptozotocin-treated rats. These data provide pharmacological validation that small molecule IRTK activators represent a potential new class of antidiabetic agents.
- Lum, Robert T.,Cheng, Mingshan,Cristobal, Cristina P.,Goldfine, Ira D.,Evans, Joseph L.,Keck, James G.,Macsata, Robert W.,Manchem, Vara Prasad,Matsumoto, Yukiharu,Park, Sophia J.,Rao, Sandhya S.,Robinson, Louise,Shi, Songyuan,Spevak, Wayne R.,Schow, Steven R.
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scheme or table
p. 6173 - 6187
(2009/10/09)
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- PHARMACEUTICAL PREPARATIONS COMPRISING INSULIN, ZINC IONS AND A ZINC-BINDING LIGAND
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Novel preparations comprising branched ligands for the HisB10 Zn2+ sites of the R-state insulin hexamer. The preparations have a prolonged action designed for flexible injection regimes.
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Page/Page column 342
(2008/06/13)
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- Novel synthesis of 5-substituted tetrazoles from nitriles
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A variety of 5-substituted tetrazoles were prepared through the respective reactions of sodium azide with corresponding nitriles in an aromatic solvent in the presence of an amine salt.
- Koguro, Kiyoto,Oga, Toshikazu,Mitsui, Sunao,Orita, Ryozo
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p. 910 - 914
(2007/10/03)
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- Process for preparation of 5- substituted tetrazoles
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The invention is directed to a process for preparing a 5-substituted tetrazole, the process comprising the step of reacting a nitrile with an inorganic azide salt in an aromatic hydrocarbon solvent in the presence of an amine salt. According to the invention, a 5-substituted tetrazole can be produced in a high yield with ease and safety using inexpensive raw materials while the reaction is easily controlled to inhibit a side reaction.
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- CHOLECYSTOKININ ANTAGONISTS
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Benzodiazepine analogs of the formula: STR1 are disclosed which are antagonists of gastrin and cholecystokinin (CCK).
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