14093-97-1Relevant academic research and scientific papers
Neuroprotective evaluation of novel substituted 1,3,4-oxadiazole and aroylhydrazone derivatives
Angelova, Violina T.,K.-Yovkova, Elena,Karabeliov, Valentin R.,Kondeva-Burdina, Magdalena S.,Vassilev, Nikolay G.
supporting information, (2022/01/20)
The paper reports on the facile and convenient synthesis of a series of novel 2,5-substituted 1,3,4-oxadiazoles 3a-f and that of aroylhydrazone-based molecular hybrids 5a-g from readily available starting materials. The structure of the compounds was confirmed by IR, 1H NMR, 13C NMR and HRESI-MS spectral data. The toxicological potential of the compounds was evaluated by monitoring the synaptosomal viability and the levels of reduced glutathione in rat brain synaptosomes, isolated by Percoll gradient. The neuroprotective effects were assessed in vitro in a model of 6-hydroxydopamine-induced neurotoxicity. Administered alone, at a concentration of 40 μM, most of the 1,3,4-oxadiazole derivatives and all of the hydrazone derivatives exhibited weak statistically significant neurotoxic effects, compared to the control. Two of the compounds from the novel oxadiazoles 3a and 3d did not have any toxicity. In a model of 6-OHDA-induced oxidative stress, again 3a and 3d and all aroylhydrazone derivatives 5a-g revealed statistically significant neuroprotective effect by preserving the synaptosomal viability and the level of reduced glutathione, against the toxic agent. Some of the compounds may have neuroprotective effects due to possible stabilization of the synaptosomal membrane and/or because of the preserved reduced glutathione. Additionally, all the compounds display a good predicted ADME profile.
Electrochemical Synthesis of 2,5-Disubstituted 1,3,4-Oxadiazoles from α-Keto Acids and Acylhydrazines Under Mild Conditions
Lu, Fangling,Gong, Fengping,Li, Liangsen,Zhang, Kan,Li, Zhen,Zhang, Xinwei,Yin, Ying,Wang, Ying,Gao, Ziwei,Zhang, Heng,Lei, Aiwen
supporting information, p. 3257 - 3260 (2020/05/25)
1,3,4-Oxadiazoles are a kind of useful heterocycles which can be frequently found in materials and bioactive molecules. In this study, intermolecular electrochemical cyclization between α-keto acids and acylhydrazines has been developed for the synthesis of 2,5-disubstituted 1,3,4-oxadiazoles with the yield up to 91 %. This transformation can be run under mild reaction conditions in the absence of external oxidant, base and transition metal catalyst. Both symmetrical and unsymmetrical 2,5-disubstituted 1,3,4-oxadiazoles could be prepared according to the careful choice of the substrate combination. Gram scale synthesis also illustrates the potential application of this protocol in large preparation.
UV-Induced 1,3,4-Oxadiazole Formation from 5-Substituted Tetrazoles and Carboxylic Acids in Flow
Green, Luke,Livingstone, Keith,Bertrand, Sophie,Peace, Simon,Jamieson, Craig
supporting information, p. 14866 - 14870 (2020/11/11)
A range of 1,3,4-oxadiazoles have been synthesized using a UV-B activated flow approach starting from carboxylic acids and 5-substituted tetrazoles. The application of UV light represents an attractive alternative to the traditional thermolytic approach and has demonstrated comparable efficiency and versatility, with a diverse substrate scope, including the incorporation of highly substituted amino acids.
Photocatalyzed facile synthesis of 2,5-diaryl 1,3,4-oxadiazoles with polyaniline-?g-C3N4-TiO2 composite under visible light
Wang, Liang,Wang, Yaoyao,Chen, Qun,He, Mingyang
supporting information, p. 1489 - 1492 (2018/03/13)
PANI (polyaniline)-g-C3N4-TiO2 composite was prepared and found to be efficient for the synthesis of 2,5-diaryl 1,3,4-oxadiazoles under visible light. This reaction involved decarboxylation and cyclization from α-keto acids with acylhydrazines, and a broad scope of substrates were tolerated to provide the desired products in moderate to good yields. Control experiments indicated that a radical pathway was involved in the present photocatalytic reaction and a synergistic effect may exist in the ternary composite. Moreover, this semiconductor photocatalyst could be readily recovered and showed good reusability with only slight decrease in the catalytic activity after six consecutive runs.
Synthesis of 2,5-disubstituted 1,3,4-oxadiazoles by visible-light-mediated decarboxylation–cyclization of hydrazides and diketones
Diao, Pinhui,Ge, Yanqin,zhang, Wenpei,Xu, Chen,Zhang, Nannan,Guo, Cheng
supporting information, p. 767 - 770 (2018/02/07)
A visible-light-induced synthesis of 2,5-disubstituted 1,3,4-oxadiazoles from simple diketones and hydrazides with the assistant of the photocatalyst eosin Y catalyzed decarboxylation and cyclization under mild conditions has been discovered. The reaction tolerates a wide range of functional groups and gives a variety of valuable 1,3,4-oxadiazoles in moderate to good yields. Finally, a plausible reaction mechanism was proposed.
METHOD FOR PREPAREING 1,3,4-OXADIAZOL UNDER SOLVENT-FREE CONDITION
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Paragraph 0074-0079; 0112-0113; 0202-0203, (2017/02/24)
The present invention relates to a synthesis method of 1,3,4-oxadiazol, comprising: 1) under a solvent-free condition and by means of a mechanical pulverization method, making a hydrazide compound react with an aldehyde compound and thereby synthesizing a N-acylhydrazone compound; and 2) under a solvent-free condition, adding an iodine-based oxidizing agent to the N-acylhydrazone compound to synthesize 1,3,4-oxadiazol via oxidative cyclization. The solventless synthesis method of 1,3,4-oxadiazol according to the present invention is easy to perform and handle, and has the advantage of synthesizing 1,3,4-oxadiazol at high selectivity and yield. Also, the solventless synthesis method of the present invention can prevent the formation of side products caused by the minute amount of water that usually remains in solvents, and can further prevent synthesized intermediates from being converted back into the starting materials by the water.COPYRIGHT KIPO 2016
One-pot cyclization/decarboxylation of α-keto acids and acylhydrazines for the synthesis of 2,5-disubstituted 1,3,4-oxadiazoles under transition-metal-free conditions
Gao, Peng,Wang, Juan,Bai, Zijing,Cheng, Hualei,Xiao, Jian,Lai, Mengnan,Yang, Desuo,Fan, Mingjin
supporting information, p. 4616 - 4619 (2016/09/23)
A one-pot KI/TBHP-mediated oxidative cyclization of α-keto acids with acylhydrazines was developed. A series of functional 2,5-disubstituted 1,3,4-oxadiazoles were synthesized through a tandem keto amine condensation followed by oxidative cyclization and decarboxylation reactions. This procedure was achieved under transition-metal-free conditions and showed advantages including readily available materials, mild reaction conditions and good group tolerance.
Study on DDQ-promoted synthesis of 2, 5-disubstituted 1, 3, 4-oxadiazoles from acid hydrazides and aldehydes
Jasiak, Karolina,Kudelko, Agnieszka,Zieliński, Wojciech,Ku?nik, Nikodem
, p. 87 - 106 (2017/02/23)
A facile stepwise synthesis of 2, 5-disubstituted 1, 3, 4-oxadiazoles proceeding via oxidative cyclization of N-acylhydrazones is reported. The reaction is efficiently promoted by 2, 3-dichloro-5, 6-dicyano-1, 4- benzoquinone (DDQ) to afford the desired products mostly in high yields and in relatively short times. The final 1, 3, 4-oxadiazole derivatives are also synthesized directly from acid hydrazides and aldehydes in a one-pot procedure. The substrate scope and limitations of the reported transformation are discussed in detail.
Palladium-Catalyzed Aminocarbonylation Reaction to Access 1,3,4-Oxadiazoles using Chloroform as the Carbon Monoxide Source
Li, Zhengyi,Wang, Liang
, p. 3469 - 3473 (2016/01/25)
A palladium-catalyzed aminocarbonylation reaction of aryl halides with chloroform and tetrazoles has been developed, where chloroform was employed as the carbon monoxide (CO) source in the presence of cesium hydroxide. The in situ generated N-acylated tetrazoles were unstable and easily decomposed to afford 2,5-disubstituted 1,3,4-oxadiazoles. A wide range of tetrazoles and aryl halides reacted smoothly under the optimized reaction conditions to give the corresponding products in moderate to good yields.
Organocatalytic Oxidative Amidation of Aldehydes with Tetrazoles to Construct 2,5-Diaryl 1,3,4-Oxadiazoles
Cao, Jing,Wang, Liang
supporting information, p. 1239 - 1243 (2015/11/27)
A practical and metal-free oxidative amidation of aldehydes with tetrazoles into 1,3,4-oxadiazoles has been developed by employing tetrabutylammonium iodide (TBAI) as catalyst and tert-butyl hydroperoxide (TBHP) as oxidant. A wide range of 2,5-disubstituted 1,3,4-oxadiazoles can be conveniently generated in moderate to good yields. Gram-scale reaction was also realized in this catalytic system..
