1594-57-6Relevant articles and documents
Mesomorphic and electrooptical properties of viologens based on non-symmetric alkyl/polyfluoroalkyl functionalization and on an oxadiazolyl-extended bent core
Pibiri, Ivana,Beneduci, Amerigo,Carraro, Mauro,Causin, Valerio,Casella, Girolamo,Corrente, Giuseppina Anna,Chidichimo, Giuseppe,Pace, Andrea,Riccobono, Alessio,Saielli, Giacomo
, p. 7974 - 7983 (2019)
Two different sets of ionic liquid crystals based on bistriflimide salts of non-symmetrically substituted polyfluorinated bipyridinium (viologens) and bent symmetrically substituted dialkyl-oxadiazolyl-bipyridinium have been synthesized, in order to study the effect on the mesomorphic and electrooptical properties of the non-symmetric functionalization (alkyl chain and fluoroalkyl chains of different lengths) on the two pyridinium rings and additionally the effect of a bent conjugated spacer among the two pyridinium units of the viologen. POM and DSC characterization show that the synthesized salts have a mesomorphic and, in some cases, polymesomorphic behaviour in a wide thermal range, also encompassing room temperature. Some of the compounds exhibit an SmA phase in addition to more ordered smectic phases at lower temperature. The presence of a fluorinated chain on one side seems to generally increase the stability of the SmA phase of the ionic liquid crystal compared to alkylated analogues of viologens. Moreover, the insertion of the bent oxadiazolyl spacer between the two pyridinium units, has a significant effect on the mesophase behaviour leading to dendritic textures recalling that of banana phases. Electrochemical characterization by cyclic voltammetry shows that the presence of a fluorinated moiety causes an easier reduction compared to typical alkyl viologens while the oxadiazolyl-bipyridinium derivatives have more negative reduction potentials. Spectroelectrochemical experiments show that in contrast to classic viologens showing a typical electrochromic band of their radical cation, the oxadiazolyl insertion between the two pyridinium moieties hampers electrochromism due to absence of resonance coupling between the N redox centers. Interestingly, electrochromism of the polyfluorinated viologens, besides being observed in solution is observed in the ionic liquid crystal smectic phase of some of the salts of this series, upon radical cation formation the spectrum exhibits a further electrochromic band in the near infrared range which is not observed in solution.
Syntheses, structural diversity and photo-physical properties of copper(I) and silver(I) coordination polymers based on the pyridine-4-amidoxime ligand
Nandy, Madhusudan,Banerjee, Sambuddha,Rizzoli, Corrado,Zangrando, Ennio,Nonat, Aline,Charbonnière, Lo?c J.,Mitra, Samiran
, p. 252 - 261 (2013)
Three new complexes, [{Cu(L)I}2]n (1), [Ag(L)] n·nClO4 (2) and [{Ag(L)(CF3COO)} 2]n (3), have been synthesised and characterized by different physico-chemical methods with the aim of exploring the ligating properties of pyridine-4-amidoxime (L). Single crystal X-ray structure analysis reveals that 1 is a 2D coordination polymer, while 2 and 3 are wavy 1D chains in spite of the same coordination mode adopted by the ligand. The crystal structures also show that the coordination geometry of the metals is different in each complex, being tetrahedral in 1, but distorted trigonal planar and distorted linear in 2 and 3, respectively. The asymmetric units of 1 and 3 consist of two independent metal centres and each is associated with a counter anion of the metal salt used, while the asymmetric unit of 2 is cationic in nature, the perchlorate anion being non-coordinated. Structural diversities are also evident as the 2D structure of 1 is stabilized by O-Ha??I interactions, while several classical and non-classical hydrogen bonds lead to 3D supra-molecular structures for complexes 2 and 3. The solid state fluorescence of L and of its complexes were studied revealing that both 1 and 2 show a broad emission band with a maxima at 525 and 522 nm, respectively, strongly red shifted when compared to the free ligand band (463 nm), while 3 is found surprisingly to be non-emissive.
Synthesis and Evaluation of Antibacterial Activity of 1,2,4-Oxadiazole-Containing Biphenylcarboxylic Acids
Baikov, S. V.,Presnukhina, S. I.,Shetnev, A. A.,Tarasenko, M. V.
, p. 1611 - 1619 (2020)
Abstract: A one-pot method for the synthesis of biphenylcarboxylic acids containing 1,2,4-oxadiazole ring in the NaOH–DMSO system was developed. The results of in vitro experiments showed that the synthesized compounds exhibit antibacterial activity against susceptible strains of E. coli and S. aureus.
Synthesis, crystal structure and characterization of (Z)-2-N′- hydroxyisonicotinamidine
Prabhuswamy,Dinesha,Pampa,Kumar, S. Madan,Nagaraja,Lokanath
, p. 243 - 252 (2014)
The compound (Z)-2-N′-hydroxyisonicotinamidine, (2) was synthesized and characterized by 1H NMR, FT-IR, FAB-Mass, UV-Visible Spectra, and elemental Analysis. Its molecular structure was solved by single crystal X-ray diffraction method. The title molecule, C6H7N3O is crystallized in the orthorhombic crystal system with the space group Pna2 1 and with unit cell parameters a = 12.5664(8) ?, b = 8.8622(6) ?, c = 5.7953(4) A, α = 90°, β; = 90°, γ = 90°, and Z = 4. The molecular and crystal structure of the title molecule is stabilized by an intramolecular interaction of the type N.HEEEO, and the intermolecular interactions of types N-H?N and O-H?N.
Molecular properties prediction and synthesis of new oxadiazole derivatives possessing 3-fluoro-4-methoxyphenyl moiety as potent anti-inflammatory and analgesic agents
Dinesha,Viveka, Shivapura,Khandige, Prasanna S.,Nagaraja, Gundibasappa K.
, p. 435 - 443 (2016)
A new series of 1,2,4- and 1,3,4-oxadiazole derivatives possessing 3-fluoro-4-methoxyphenyl moiety were efficiently synthesized and characterized by spectroscopic methods and elemental analysis. All the compounds were evaluated in vivo for their anti-infl
Liquid crystalline pyridine containing 1,2,4-oxadiazoles
Karamysheva, Ludmila A.,Agafonova, Irina F.,Torgova, Sofia I.,Umanskii, Boris A.,Strigazzi, Alfredo
, p. 547 - 556 (2001)
New mesomorphic 1,2,4-oxadiazoles containing as an electron-acceptor substituent the pyridine cycle with different position of the nitrogen atom with respect to the oxadiazole cycle have been synthesized. The reaction of the isonicotinic and nicotinic ami
Novel O-acylated amidoximes and substituted 1,2,4-oxadiazoles synthesised from (+)-ketopinic acid possessing potent virus-inhibiting activity against phylogenetically distinct influenza A viruses
Borisevich, Sophia S.,Chernyshov, Vladimir V.,Esaulkova, Iana L.,Popadyuk, Irina I.,Salakhutdinov, Nariman F.,Sinegubova, Ekaterina,Yarovaya, Olga I.,Zarubaev, Vladimir V.
, (2021/12/16)
This article describes the synthesis and antiviral activity evaluation of new substituted 1,2,4-oxadiazoles containing a bicyclic substituent at position 5 of the heterocycle and O-acylated amidoximes as precursors for their synthesis. New compounds were
SUBSTITUTED 1,2,4-OXADIAZOLES AS SMALL MOLECULE INHIBITORS OF UBIQUITIN-SPECIFIC PROTEASE 28
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Paragraph 00195, (2022/02/28)
The present disclosure relates to a compound of formula (I) or a pharmaceutically acceptable salt thereof, and to a pharmaceutical composition comprising a compound of formula (I) and a pharmaceutically acceptable carrier. The disclosure also relates to a method of treating a disease or disorder associated with ubiquitin-specific protease 28 (USP28) a method of treating cancer, and a method of inhibiting USP28, comprising administering to a subject in need thereof a compound of formula (I).
2-(1,2,4-Oxadiazol-5-yl)anilines Based on Amidoximes and Isatoic Anhydrides: Synthesis and Structure Features
Baykov, S. V.,Kotlyarova, V. D.,Shetnev, A. A.,Tarasenko, M. V.
, p. 768 - 778 (2021/06/26)
Abstract: An efficient one-pot method was developed for the synthesis of 2-(1,2,4-oxadiazol-5-yl)anilines via the reaction of amidoximes with isatoic anhydrides in a NaOH–DMSO medium at ambient temperature. The method allows to obtain structurally diverse
Convenient one-pot synthesis of 1,2,4-oxadiazoles and 2,4,6-triarylpyridines using graphene oxide (GO) as a metal-free catalyst: Importance of dual catalytic activity
Basak, Puja,Dey, Sourav,Ghosh, Pranab
, p. 32106 - 32118 (2021/12/02)
A convenient and efficient process for the synthesis of 3,5-disubstituted 1,2,4-oxadiazoles and 2,4,6-triarylpyridines has been described using an inexpensive, environmentally benign, metal-free heterogeneous carbocatalyst, graphene oxide (GO). GO plays a dual role of an oxidizing agent and solid acid catalyst for synthesizing 1,2,4-oxadiazoles and triarylpyridines. This dual catalytic activity of GO is due to the presence of oxygenated functional groups which are distributed on the nanosheets of graphene oxide. A broad scope of substrate applicability and good sustainability is offered in this developed protocol. The results of a few control experiments reveal a plausible mechanism and the role of GO as a catalyst was confirmed by FTIR, XRD, SEM, and HR-TEM analysis.
