- Synthesis of 1,3,4-oxadiazole and xanthen-2-one luminophoric epoxide monomers
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Epoxide derivatives of 2,5-bis-oxyphenyl-1,3,4-oxadiazoles and fluorescein, which are luminescent epoxide monomers, are synthesized. Their luminescence properties are studied. 1999 KluwerAcademic/Plenum Publishers.
- Korotkikh,Shvaika,Gorbunov
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- Synthesis, liquid-crystalline, photophysical and chemosensor properties of oxadiazole/thiadiazole-based amphiphiles with glycerol groups
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Two series of heterocycle-based mesogens consisting of a long 2,5-diphenyl-1,3,4-oxadiazole/thiadiazole rigid core with three lipophilic and flexible alkyl chains at one end and a polar glycerol group at the opposite end have been synthesized via one pot cyclization reaction. These compounds were investigated by polarizing optical microscopy (POM), differential scanning calorimetry (DSC), X-ray scattering, cyclic voltammetry, UV–vis spectroscopy and photoluminescence measurements. Upon elongation of the alkyl chains, a transition from hexagonal columnar phase to Pm3ˉn-type cubic phase was observed in both series. Oxadiazole series are blue luminescent LCs with binding selectivity to Li+, while thiadiazole series are blue-green luminescent LCs with binding selectivity to Fe3+.
- Xiao, Yulong,Gao, Hongfei,Wang, Tingyan,Zhang, Ruilin,Cheng, Xiaohong
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- Rapid synthesis of 2,5-disubstituted 1,3,4-oxadiazoles under microwave irradiation
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A number of symmetrically 2,5-disubstituted 1,3,4-oxadiazoles are quickly prepared by the reaction of aromatic acids with hydrazine dihydrochloride in a mixture of orthophosphoric acid and phosphorus pentoxide under microwave irradiation.
- Bentiss, Fouad,Lagrenee, Michel,Barbry, Didier
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- Oxidative cyclization of aldazines with bis(trifluoroacetoxy)iodobenzene
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Symmetrical and unsymmetrical aldazines are efficiently converted to 2,5-disubstituted-1,3,4-oxadiazoles by oxidation with bis(trifluoroacetoxy) iodobenzene (BTI).
- Shang, Zhenhua,Reiner, John,Chang, Junbiao,Zhao, Kang
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- Study of heterogeneous catalysis by iron-squarate based 3d metal organic framework for the transformation of tetrazines to oxadiazole derivatives
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We present here a simple, milder, and environmentally benign heterogeneous catalytic method for the transformation of tetrazines to oxadiazole derivatives at room temperature (25 °C) using our earlier synthesized iron-squarate based 3D metal organic framework, [Fe3(OH)3(C 4O4)(C4O4)0.5] n (FeSq-MOF).
- Goswami, Soumyabrata,Jena, Himanshu Sekhar,Konar, Sanjit
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- The effects of asymmetric bent-shaped compounds on the temperature range and electro-optical performances of liquid crystalline blue phases
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A series of asymmetric and symmetric bent-shaped molecules with branched terminals were synthesized and characterized. Their effects on inducing blue phase and electro-optical performances were compared and analyzed experimentally. It was found that the asymmetric and symmetric compounds almost have the same effect on inducing and stabilizing blue phase, but the electro-optical performance of mixtures doped with asymmetric compounds are much better than that of mixtures doped with symmetric compounds for they have a totally different dielectric anisotropy which can contribute to a larger Kerr constant.
- Wang, Xin,He, Wan-Li,Yang, Zhou,Wang, Dong,Cao, Hui,Zheng, Zhi-Gang,Liu, Zhen,Liu, Xiang
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p. 110750 - 110757
(2016)
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- Electrochemical oxidation of aldehyde-N-arylhydrazones into symmetrical-2,5-disubstituted-1,3,4-oxadiazoles
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A convenient, efficient and one-pot synthesis of chemically and pharmaceutically interesting symmetrical-2,5-disubstituted-1,3,4-oxadiazoles is reported. The protocol involves anodic oxidation of aldehyde-N-arylhydrazones in anhyd. MeCN-LiClO4. Constant potential electrolysis carried out in an undivided cell and platinum electrodes leads to the formation of the corresponding oxadiazoles under ambient condition and the mechanism was deduced from voltammetry studies. The reaction proceeded smoothly with high atom economy. Springer Science+Business Media Dordrecht 2013.
- Singh, Sushma,Sharma, Laxmi K.,Saraswat, Apoorv,Siddiqui, Ibadur R.,Singh, Rana K. Pal
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p. 947 - 960
(2014/05/06)
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- Electrosynthesis and screening of novel 1,3,4-oxadiazoles as potent and selective antifungal agents
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The electrochemical oxidation of aldehyde-N-aroylhydrazone has been studied in the presence of NaClO4 as supporting electrolyte in MeOH solution using cyclic voltammetry and controlled potential electrolysis. The results indicate that intramolecular cyclization of aldehyde-N-aroylhydrazone has been successfully performed at a platinum electrode in an undivided cell with good yields of the corresponding 1,3,4-oxadiazoles at ambient conditions. The reaction products were characterized by spectroscopic methods and a mechanism was deduced from voltammetry studies. The antifungal activity of the synthesized compounds was evaluated on Fusarium oxysporum, Alternaria solani, Candida albicans and Aspergillus niger. The results revealed that all the synthesized compounds have significant antifungal activity against the tested fungi. Among the synthesized derivatives 7b, 7d, 7g, 7h, 7i, 7j and 7r were found to be the most effective antifungal compounds. The Royal Society of Chemistry 2013.
- Singh, Sushma,Sharma, Laxmi Kant,Saraswat, Apoorv,Siddiqui, Ibadur R.,Kehri, Harbans K.,Singh, Rana K. Pal
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p. 4237 - 4245
(2013/05/08)
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- Bent-core systems based on [1,3,4]oxadiazole core with shape biaxiality
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The present paper is presenting the Synthesis and characterization of new [1,3,4]oxadiazole derivatives obtained by attaching different mesogenic units to the central core. Liquid crystals properties analysis by POM and DSC techniques is presented and structure-properties correlations are discussed.
- Apreutesei, Daniela,Mehl, Georg H.
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experimental part
p. 527 - 533
(2009/12/24)
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- A new synthesis of symmetrical 2,5-disubstituted 1,3,4- oxadiazoles
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Several new 2,5-disubstituted 1,3,4-oxadiazoles have been synthesized in good yields by reaction of aromatic acids with hydrazine dihydrochloride in a mixture of orthophosphoric acid, phosphorus pentoxide and, in general, with addition of phosphorus oxychloride to the reaction mixture. The structures of new oxadiazoles derivatives were confirmed by analytical and spectral data.
- Bentiss, Fouad,Lagrenee, Michel
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p. 1029 - 1032
(2007/10/03)
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- Poly(1,3,4-oxadiozoles) via aromatic nucleophilic displacement
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Poly(1,3,4-oxadiazoles) (POX) are prepared by the aromatic nucleophilic displacement reaction of di(hydroxyphenyl)-1,3,4-oxadiazole monomers with activated aromatic dihalides or activated aromatic dinitro compounds. The polymerizations are carried out in
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- New developments in thermally stable polymers
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Advances in high-temperature polymers since 1985 are discussed with the emphasis on the chemistry.High-temperature polymers refer to materials that exhibit glass-transition temperatures > 200 deg C and have the chemical structure expected to provide high thermooxidative stability.Specific polymers or series of polymers were selected to show how the chemical structure influences certain properties.Poly(arylene ethers) and polyimides are the two principal families of polymers discussed.Recent work on poly(arylene ethers) has concentrated on incorporating heterocyclic units within the polymer backbone.Recent polyimide work has centered on the synthesis of new polymers from novel monomers, several containing the trifluoromethyl group strategically located on the molecule.Various members in each of these polymer families display a unique combination of properties, heretofore unattainable.Other families of polymers are also briefly discussed with a polymer from an AB maleimidobenzocyclobutene exhibiting an especially attractive combination of properties.
- Hergenrother, Paul M.
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p. 481 - 491
(2007/10/02)
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