Journal articles: '4-oxadiazoly'

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Stepanova, Elena V., and Andrei I. Stepanov. "UNUSUAL WAY OF REACTION OF 3-AMINO-4-(5-CHLOROMETHYL-1,2,4-OXADIAZOLE-3-YL)-FURAZAN WITH HYDRAZINE." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENIY KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 60, no. 4 (May 12, 2017): 26. http://dx.doi.org/10.6060/tcct.2017604.5522.

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The results of our study of the pathways of selective reactivity of 3-amino-4-(5-chloromethyl-1,2,4-oxadiazole-3-yl)furazan versus 5-unsubstituted or 5-methyl and 5-trifluoromethyl substituted 4-(5R-1,2,4-oxadiazole-3-yl)furazans (R = H, Me, CF3) towards the action of hydrazine are discussed. If the reductive opening of 1,2,4-oxadiazole ring in unsubstituted at the С-5 atom (1,2,4-oxadiazol-3-yl)furazan derivatives under the treatment with hydrazine can be used as a method for the preparation of a range of amidrazones of 4-R-furazan-3-carboxylic acid. 3-amino-4-(5-trifluoromethyl-1,2,4-oxadiazol-3-yl)furazan with hydrazine gives amidoxime of 4-aminofurazan-3-carboxylic acid. 3-amino-4-(5-methyl-1,2,4-oxadiazol-3-yl) furazan is inert to the action of hydrazine, on the contrary the reaction of 3-amino-4-(5-chloromethyl-1,2,4-oxadiazole-3-yl)furazan with hydrazine leads to oxidation of chloromethyl group of titled compound to the carbonyl one. In this case the product of reaction of 3-amino-4-(5-chloromethyl-1,2,4-oxadiazole-3-yl)furazan with hydrazine was isolated in a form of corresponding hydrazonomethyl derivative notably as 3-amino-4-(5-hydrazonomethyl-1,2,4-oxadiazole-3-yl)furazan. A possible reaction mechanism for the formation of hydrazonomethyl group by oxidation reaction of chloromethyl group by hydrazine is proposed. 3-Amino-4-(5-hydrazonomethyl-1,2,4-oxadiazol-3-yl)furazan undergoes a transhydrazination reaction with semicarbazide and thiosemicarbazide. But our attempts to its hydrolysis for the purpose to obtain free aldehyde were unsuccessful. Thus, hydrolysis of hydrazonomethyl derivative in acetic acid in the presence of catalytic amount of sulfuric acid results in azine – N,N'-bis(3-(4-aminofurazan-3-yl)-1,2,4-oxadiazol-5-ylmethylyden)hydrazine – precipitation, long-duration boiling in hydrochloric acid leads to Kishner-Wolff reduction of the carbonyl group to 3-amino-4-(5-methyl-1,2,4-oxadiazol-3-yl)furazan, and hydrolysis in alkaline medium leads to 1,2,4-oxadiazole ring opening to amidoxime of 4-aminofurazan-3-carboxylic acid. Synthesis of 3-amino-4-(5-chloromethyl-1,2,4-oxadiazole-3-yl)furazan (R = CH2Cl) was carried out by condensation of amidoxime of 4-aminofurazan-3-carboxylic acid with an excess of chloroacetyl chloride in toluene at elevated temperature. The reaction proceeds through formation of intermediate product – 3-chloromethylamino-4-(5-chloromethyl-1,2,4-oxadiazol-3-yl)furazan. Removing of N-chloroacetyl group in such obtained intermediate was performed by hydrolysis in acidic media. One-pot synthesis without the need for isolation and purification of intermediate is allowed. The structures of obtained compounds were proved by modern methods of physical-chemical analysis (1H, 13C NMR, IR and MS spectroscopy).Forcitation:Stepanova E.V., Stepanov A.I. Unusual way of reaction of 3-amino-4-(5-chloromethyl-1,2,4-oxadiazole-3-yl)furazan with hydrazine. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 4. P. 26-32.

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Ahsan, Mohamed Jawed, Arun Choupra, Rakesh Kumar Sharma, Surender Singh Jadav, Pannala Padmaja, Mohd Zaheen Hassan, Abdulmalik Bin Saleh Al-Tamimi, Mohammed H. Geesi, and Mohammed Afroz Bakht. "Rationale Design, Synthesis, Cytotoxicity Evaluation, and Molecular Docking Studies of 1,3,4-oxadiazole Analogues." Anti-Cancer Agents in Medicinal Chemistry 18, no. 1 (March 16, 2018): 121–38. http://dx.doi.org/10.2174/1871520617666170419124702.

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Background: 1,3,4-Oxadiazole heterocycles possess a broad spectrum of biological activities. They were reported as potent cytotoxic agents and tubulin inhibitors; hence it is of great interest to explore new oxadiazoles as cytotoxic agents targeting tubulin polymerization. Objective: Two new series of oxadiazoles (5a-h and 12a-h) were synthesized, structurally related to the heterocyclic linked aryl core of IMC-038525, NSC 776715, and NSC 776716, with further modification by incorporating methylene linker. Method: The 2,5-disubstituted-1,3,4-oxadiazoles (5a-h and 12a-h) were synthesized by refluxing an equimolar mixture of the intermediates [(4) and (8a-d)] and aromatic aldehydes in water-ethanol system using sodium bisulphite catalyst. The cytotoxicity evaluation was carried out according to the National Cancer Institute (NCI US) Protocol, while the tubulin polymerization assay kits from Cytoskeleton ™(bk011p) was used to perform an in vitro tubulin polymerization assay. Results: 2-(5-{[(4-Chlorophenyl)amino]methyl}-1,3,4-oxadiazol-2-yl)phenol (5f) and 2-[(2,4-dichlorophenoxy) methyl]-5-(3,4-dimethoxyphenyl)-1,3,4-oxadiazole (12c) showed maximum cytotoxicity with the mean percent growth inhibitions (GIs) of 71.56 and 72.68 respectively at 10 µM drug concentrations. Both the compounds (5f and 12c) showed superior cytotoxicity than clinically prevalent anticancer drugs, Imatinib and Gefitinib in one dose assay. The compound 12c showed promising results in five dose assay, with GI50 values varies between 1.61 and >100 µM. Furthermore, the compounds, 5f and 12c also inhibited the polymerization of tubulin with, an IC50 of 2.8 and 2.2 µM, respectively. Conclusion: The oxadiazoles reported herein are tubulin inhibitors and cytotoxic agents. These findings will be helpful in future drug design of more potent tubulin inhibitor cytotoxic agents.

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Mohammadi-Khanaposhtani, Maryam, Kiana Fahimi, Elahe Karimpour-Razkenari, Maliheh Safavi, Mohammad Mahdavi, Mina Saeedi, and Tahmineh Akbarzadeh. "Design, Synthesis and Cytotoxicity of Novel Coumarin-1,2,3-triazole-1,2,4- Oxadiazole Hybrids as Potent Anti-breast Cancer Agents." Letters in Drug Design & Discovery 16, no. 7 (June 27, 2019): 818–24. http://dx.doi.org/10.2174/1570180815666180627121006.

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Background: This work reports design, synthesis, and in vitro cytotoxicity of novel coumarin-1,2,3-triazole-1,2,4-oxadiazole hybrids against three breast cancer cell lines MCF-7, MDA-MB-231, and T-47D. Methods: Synthetic procedure for the preparation of desired compounds was started from the reaction of coumarins or with propargyl bromide to give O-propargylated coumarins or 5. Then, click reaction between the later compounds and 3-aryl-5-(chloromethyl)-1,2,4-oxadiazoles afforded the desired products in good yields. Results: Among the synthesized compounds, 4-((1-((3-(4-chlorophenyl)-1,2,4-oxadiazol-5- yl)methyl)-1H-1,2,3-triazol-4-yl)methoxy)-2H-chromen-2-one (9a) showed the best cytotoxicity against breast cancer cell lines. Conclusion: Compound 9a depicted the most activity toward MDA-MB-231 and T-47D cells while compounds 8a and 8c were the most potent compounds against MCF-7.

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Saini, Sachin. "Synthesis and Anticonvulsant Studies of Thiazolidinone and Azetidinone Derivatives from Indole Moiety." Drug Research 69, no. 08 (December 20, 2018): 445–50. http://dx.doi.org/10.1055/a-0809-5098.

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Abstract2-Amino-5-(3’-indolomethylene)-1, 3 , 4 - oxadiazole (3) undergoes facile condensation with various aromatic aldehydes to gave 2-substitiuted arylidenylamino-5-(3’- indolomethylene) – 1, 3 , 4 – oxadiazole (4–8). Cyclocondensation of (4–8) with thioglycolic acid and triethylamine yielded 3-[5’-(3”- indolomethylene)- 1’, 3’, 4’- oxadiazol-2’-yl]- 2- (substituted aryl)-4- thiazolidinones (9–13) and 1-[5’-(3”- indolomethylene) -1’, 3’, 4’- oxadiazol - 2’- yl ] -4-(substituted aryl) -2- azetidinones (14–18). The structures of these compounds were established on the basis of analytical and spectral data. The newly synthesised compounds were evaluated for their anticonvulsant activity and acute toxicity.

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Godovikova, T. I., S. K. Vorontsova, L. D. Konyushkin, S. I. Firgang, and O. A. Rakitin. "4-Methyl-1,2,5-oxadiazole-3-carbonitrile in the synthesis of 1,2,5-oxadiazolyl-1,2,4-oxadiazoles." Russian Chemical Bulletin 57, no. 11 (November 2008): 2440–42. http://dx.doi.org/10.1007/s11172-008-0349-4.

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6

Tang, Yongxing, Chunlin He, Lauren A. Mitchell, Damon A. Parrish, and Jean'ne M. Shreeve. "Energetic compounds consisting of 1,2,5- and 1,3,4-oxadiazole rings." Journal of Materials Chemistry A 3, no. 46 (2015): 23143–48. http://dx.doi.org/10.1039/c5ta06898c.

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3-Nitroamino-4-(5-amino-1,3,4-oxadiazol-2-yl)furazan monohydrate (2·H₂O), which is a combination of the nitroaminofurazan and 1,3,4-oxadiazole rings, was obtained by the nitration of 3-amino-4-(5-amino-1,3,4-oxadiazol-2-yl)furazan (1) with 100% nitric acid.

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Ahsan, Mohamed Jawed, Mohd Zaheen Hassan, Surender Singh Jadav, Mohammed H. Geesi, Mohammed Afroz Bakht, Yassine Riadi, Salahuddin, Md Sayeed Akhtar, Mohammad Nasar Mallick, and Md Habban Akhter. "Synthesis and Biological Potentials of 5-aryl-N-[4-(trifluoromethyl) phenyl]-1,3,4-oxadiazol-2-amines." Letters in Organic Chemistry 17, no. 2 (January 7, 2020): 133–40. http://dx.doi.org/10.2174/1570178616666190401193928.

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Oxadiazoles are an important class of heterocyclic compounds, having broad-spectrum activity. They were also reported as anticancer, and antioxidant agents, hence it is of significant importance to explore new oxadiazoles. A series of eleven (5-aryl-N-[4-(trifluoromethyl)phenyl]-1,3,4- oxadiazol-2-amines (6a-k) was synthesized based on the structures of reported compounds, SU-101, IMC38525, and FTAB. All these oxadiazoles were synthesized, characterized by spectral data, and further tested against melanoma, leukemia, colon, lung, CNS, ovarian, renal, breast and prostate cancer cell lines’ panels at a single dose of 10 μM drug concentrations. N-(4-(Trifluoromethyl)phenyl)-5-(3,4- dimethoxyphenyl)-1,3,4-oxadiazol-2-amine (6h) showed significant anticancer activity, and the most sensitive five cell lines were NCI-H522 (% GI = 53.24), K-562 (% GI = 47.22), MOLT-4 (% GI = 43.87), LOX-IMVI (% GI = 43.62), and HL-60(TB) (% GI = 40.30). The compound, 6h revealed better %GIs than imatinib, against 36 cell lines, taking 54 cell lines in common. The maximum sensitivity was recorded against cancer cell line CCRF-CEM (% GI = 68.89) by 2-(5-(4-(trifluoromethyl) phenylamino)-1,3,4-oxadiazol-2-yl)phenol (6f). The antioxidant activity of 4-(5-(4-(trifluoromethyl) phenylamino)-1,3,4-oxadiazol-2-yl)-2-methoxyphenol (6i) was promising with an IC50 of 15.14 μM. It was observed that the oxadiazoles reported herein showed significant anticancer and antioxidant activities.

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Yadav, Mange, Shrikant Shirude, Devendra Puntambekar, Pinkal Patel, Hetal Prajapati, Arvind Parmar, R. Balaraman, and Rajani Giridhar. "Studies in 3,4-diaryl-1,2,5-oxadiazoles and their N-oxides: Search for better COX-2 inhibitors." Acta Pharmaceutica 57, no. 1 (March 1, 2007): 13–30. http://dx.doi.org/10.2478/v10007-007-0002-z.

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Studies in 3,4-diaryl-1,2,5-oxadiazoles and theirN-oxides: Search for better COX-2 inhibitorsA series of 3,4-diaryl-1,2,5-oxadiazoles and 3,4-diaryl-1,2,5-oxadiazoleN-oxides were prepared and evaluated for COX-2 and COX-1 binding affinityin vitroand for anti-inflammatory activity by the rat paw edema method.p-Methoxy (p-OMe) substituted compounds 9, 21, 34, 41, 42 showed COX-2 enzyme inhibition higher than that showed by compounds with other substituents. 3,4-Di(4-methoxyphenyl)-1,2,5-oxadiazoleN-oxide (42) showed COX-2 enzyme inhibition of 54% at 22 μmol L-1and COX-1 enzyme inhibition of 44% at 88 μmol L-1concentrations, but showed very lowin vivoanti-inflammatory activity. Its deoxygenated derivative (21) showed lower COX-2 enzyme inhibition (26% at 22 μmol L-1) and higher COX-1 enzyme inhibition (53% at 88 μmol L-1) but, markedin vivoanti-inflammatory activity (71% at 25 mg kg-1)vs.celecoxib (48% at 12.5 mg kg-1). Molecular modeling (docking) studies showed that the methoxy group is positioned in the vicinity of COX-2 secondary pocket and it also participates in hydrogen bonding interactions in the COX-2 active site. These preliminary studies suggest thatp-methoxy (p-OMe) group in one of benzene rings may give potentially active leads in this series of oxadiazole/N-oxides.

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Jin, Guoxia, Yuqi Ji, Teng Wang, Yanyan Sun, Yulong Li, Guiying Zhu, and Jianping Ma. "Syntheses and characterization of dinuclear and tetranuclear AgI supramolecular complexes generated from symmetric and asymmetric molecular clips containing oxadiazole rings." Acta Crystallographica Section C Structural Chemistry 75, no. 10 (September 6, 2019): 1327–35. http://dx.doi.org/10.1107/s2053229619011744.

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A new asymmetric ligand, 5-{3-[5-(4-methylphenyl)-1,3,4-oxadiazol-2-yl]phenyl}-2-(pyridin-3-yl)-1,3,4-oxadiazole (L5), which contains two oxadiazole rings, was synthesized and characterized. The assembly of symmetric 2,5-bis(pyridin-3-yl)-1,3,4-oxadiazole (L1) and asymmetric L5 with AgCO2CF3 in solution yielded two novel AgI complexes, namely catena-poly[[di-μ-trifluoroacetato-disilver(I)]-bis[μ-2,5-bis(pyridin-3-yl)-1,3,4-oxadiazole]], [Ag2(C2F3O2)2(C12H8N4O)2] n or [Ag2(μ2-O2CCF3)2(L1)2] n (1), and bis(μ3-5-{3-[5-(4-methylphenyl)-1,3,4-oxadiazol-2-yl]phenyl}-2-(pyridin-3-yl)-1,3,4-oxadiazole)tetra-μ3-trifluoroacetato-tetrasilver(I) dichloromethane monosolvate, [Ag4(C2F3O2)4(C22H15N5O2)2]·CH2Cl2 or [Ag2(μ3-O2CCF3)2(L5)]2·CH2Cl2 (2). Complex 1 displays a one-dimensional ring–chain motif, where dinuclear Ag2(CF3CO2)2 units alternate with Ag2(L1)2 macrocycles. This structure is different from previously reported Ag–L1 complexes with different anions. Complex 2 features a tetranuclear supramolecular macrocycle, in which each ligand adopts a tridentate coordination mode with the oxadiazole ring next to the p-tolyl ring coordinated and that next to the pyridyl ring free. Two L5 ligands are bound to two Ag1 centres through two oxadiazole N and two pyridyl N atoms to form a macrocycle. The other two oxadiazole N atoms coordinate to the two Ag2 centres of the Ag2(O2CCF3)4 dimer. Each CF3CO2 − anion adopts a μ3-coordination mode, bridging the Ag1 and Ag2 centres to form a tetranuclear silver(I) complex. This study indicates that the donor ability of the bridging oxadiazole rings can be tuned by electron-withdrawing and -donating substituents. The emission properties of ligands L1 and L5 and complexes 1 and 2 were also investigated in the solid state.

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Yurttaş, Leyla, Betül K. Çavuşoğlu, Gülşen A. Çiftçi, and Halide E. Temel. "Synthesis and Biological Evaluation of New 1,3,4-Oxadiazoles as Potential Anticancer Agents and Enzyme Inhibitors." Anti-Cancer Agents in Medicinal Chemistry 18, no. 6 (November 12, 2018): 914–21. http://dx.doi.org/10.2174/1871520618666180322123327.

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Background: 1,3,4-Oxadiazoles have been known with a wide variety of pharmacological activities including anticancer activity. Objective: In this study, novel 2,5-disubstituted 1,3,4-oxadiazole derivatives were synthesized and evaluated for determining their anticancer, anticholinesterase and lipoxygenase (LOX) inhibitory activity. Methods: All compounds were tested against C6 rat glioma, A549 human lung carcinoma and NIH/3T3 mouse embryo fibroblast cell lines to define cytotoxic concentrations and apoptosis induction levels which they cause. Results: Many of the compounds exhibited remarkable potency that compounds 2a, 2b, 2e, 2h and 2j against C6 cells and compounds 2a, 2b, 2d, 2g, 2i, 2j against A549 cells were found more active than cisplatin. Compound 2d namely, 2-[(5-(4-aminophenyl)-1,3,4-oxadiazol-2-yl)thio]-1-(4-chlorophenyl)ethan-1-one induced apoptosis of A549 cells with 74.9% whereas cisplatin caused 70.9% percentage. Conclusion: Among them, compounds 2d and 2j against A549 cell line, compounds 2b and 2e against both tumor cell lines showed selective cytotoxicity evaluating the inhibition concentration against NIH/3T3 cell line. None of the compounds showed significant acetylcholinesterase (AChE) and lipoxygenase inhibitory activities.

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Maftei, Catalin V., Elena Fodor, Peter G. Jones, M. Heiko Franz, Gerhard Kelter, Heiner Fiebig, and Ion Neda. "Synthesis and characterization of novel bioactive 1,2,4-oxadiazole natural product analogs bearing the N-phenylmaleimide and N-phenylsuccinimide moieties." Beilstein Journal of Organic Chemistry 9 (October 25, 2013): 2202–15. http://dx.doi.org/10.3762/bjoc.9.259.

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Taking into consideration the biological activity of the only natural products containing a 1,2,4-oxadiazole ring in their structure (quisqualic acid and phidianidines A and B), the natural product analogs 1-(4-(3-tert-butyl-1,2,4-oxadiazol-5-yl)phenyl)pyrrolidine-2,5-dione (4) and 1-(4-(3-tert-butyl-1,2,4-oxadiazol-5-yl)phenyl)-1H-pyrrole-2,5-dione (7) were synthesized starting from 4-(3-tert-butyl-1,2,4-oxadiazol-5-yl)aniline (1) in two steps by isolating the intermediates 4-(4-(3-tert-butyl-1,2,4-oxadiazol-5-yl)phenylamino)-4-oxobutanoic acid (3) and (Z)-4-(4-(3-tert-butyl-1,2,4-oxadiazol-5-yl)phenylamino)-4-oxobut-2-enoic acid (6). The two natural product analogs 4 and 7 were then tested for antitumor activity toward a panel of 11 cell lines in vitro by using a monolayer cell-survival and proliferation assay. Compound 7 was the most potent and exhibited a mean IC50 value of approximately 9.4 µM. Aniline 1 was synthesized by two routes in one-pot reactions starting from tert-butylamidoxime and 4-aminobenzoic acid or 4-nitrobenzonitrile. The structures of compounds 1, 2, 4, 5 and 6 were confirmed by X-ray crystallography.

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Pagoria, Philip, Maoxi Zhang, Ana Racoveanu, Alan DeHope, Roman Tsyshevsky, and Maija Kuklja. "3-(4-Amino-1,2,5-oxadiazol-3-yl)-4-(4-nitro-1,2,5-oxadiazol-3-yl)-1,2,5-oxadiazole." Molbank 2014, no. 2 (May 22, 2014): M824. http://dx.doi.org/10.3390/m824.

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Wu, Xiang-Wen, Meng-Meng Xin, Jian-Ping Ma, Zhen-Hua Wu, and Yu-Bin Dong. "The coordination chemistry of two symmetric double-armed oxadiazole-bridged organic ligands with copper salts." Acta Crystallographica Section C Crystal Structure Communications 69, no. 6 (May 15, 2013): 601–5. http://dx.doi.org/10.1107/s0108270113010913.

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Two new symmetric double-armed oxadiazole-bridged ligands, 4-methyl-{5-[5-methyl-2-(pyridin-3-ylcarbonyloxy)phenyl]-1,3,4-oxadiazol-2-yl}phenyl pyridine-3-carboxylate (L1) and 4-methyl-{5-[5-methyl-2-(pyridin-4-ylcarbonyloxy)phenyl]-1,3,4-oxadiazol-2-yl}phenyl pyridine-4-carboxylate (L2), were prepared by the reaction of 2,5-bis(2-hydroxy-5-methylphenyl)-1,3,4-oxadiazole with nicotinoyl chloride and isonicotinoyl chloride, respectively. LigandL1 can be used as an organic clip to bind CuIIcations and generate a molecular complex, bis(4-methyl-{5-[5-methyl-2-(pyridin-3-ylcarbonyloxy)phenyl]-1,3,4-oxadiazol-2-yl}phenyl pyridine-3-carboxylate)bis(perchlorato)copper(II), [Cu(ClO4)2(C28H20N4O5)2], (I). In compound (I), the CuIIcation is located on an inversion centre and is hexacoordinated in a distorted octahedral geometry, with the pyridine N atoms of twoL1 ligands in the equatorial positions and two weakly coordinating perchlorate counter-ions in the axial positions. The two arms of theL1 ligands bend inward and converge at the CuIIcoordination point to give rise to a spirometallocycle. LigandL2 binds CuIcations to generate a supramolecule, diacetonitriledi-μ3-iodido-di-μ2-iodido-bis(4-methyl-{5-[5-methyl-2-(pyridin-4-ylcarbonyloxy)phenyl]-1,3,4-oxadiazol-2-yl}phenyl pyridine-4-carboxylate)tetracopper(I), [Cu4I4(CH3CN)2(C28H20N4O5)2], (II). The asymmetric unit of (II) indicates that it contains two CuIatoms, oneL2 ligand, one acetonitrile ligand and two iodide ligands. Both of the CuIatoms are four-coordinated in an approximately tetrahedral environment. The molecule is centrosymmetric and the four I atoms and four CuIatoms form a rope-ladder-type [Cu4I4] unit. Discrete units are linked into one-dimensional chains through π–π interactions.

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Kysil, Andrii, Angelina Biitseva, Oleksandra Bugera, Tetyana Yegorova, and Zoia Voitenko. "Synthesis of 2-(1,2,4-oxadiazol-5-yl)-2,3-dihydro-4H-chromen-4-ones." French-Ukrainian Journal of Chemistry 8, no. 2 (2020): 176–82. http://dx.doi.org/10.17721/fujcv8i2p176-182.

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Simple and efficient synthesis of 2-(1,2,4-oxadiazol-5-yl)-2,3-dihydro-4H-chromen-4-ones is elaborated. The method relies on CDI-mediated cyclocondensation of substituted 4-oxochromane-2-carboxylic acids and amidoximes. The protocol allows the preparation of 2-oxadiazolylchromanones decorated with two pharmacophores (2,3-dihydro-4H-chromen-4-one and 1,2,4-oxadiazole) that are in high demand in drug discovery.

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Wołek, Barbara, Mateusz Werłos, Magdalena Komander, and Agnieszka Kudelko. "Efficient Synthesis of Novel 1,3,4-Oxadiazoles Bearing a 4-N,N-Dimethylaminoquinazoline Scaffold via Palladium-Catalyzed Suzuki Cross-Coupling Reactions." Molecules 25, no. 21 (November 5, 2020): 5150. http://dx.doi.org/10.3390/molecules25215150.

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Two series of novel (symmetrical and unsymmetrical) quinazolinylphenyl-1,3,4-oxadiazole derivatives were synthesized using palladium-catalyzed Suzuki cross-coupling reactions. The presented synthetic methodology is based on the use of bromine-substituted 2-phenyl-4-N,N-dimethylaminoquinazolines and either a boronic acid pinacol ester or a diboronic acid bis(pinacol) ester of 2,5-diphenyl-1,3,4-oxadiazole. The reactions are conducted in a two-phase solvent system in the presence of catalytic amounts of [1,1′-bis(diphenylphosphino)ferrocene]-dichloropalladium(II), sodium carbonate, and tetrabutylammonium bromide, which plays the role of a phase-transfer catalyst. The luminescence properties of the obtained compounds are discussed in the context of applying these compounds in optoelectronics. Specifically, two highly-conjugated final products: N,N-dimethyl-2-phenyl-6-(4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenyl)quinazolin-4-amine (8f) and 6,6′-(4,4′-(1,3,4-oxadiazole-2,5-diyl)bis(4,1-phenylene))bis(N,N-dimethylquinazolin-4-amine (9f), which contain a 1,3,4-oxadiazole moiety connected to a quinazoline ring by a 1,4-phenylene linker at the 6 position, exhibit strong fluorescence emission and high quantum yields.

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Mercer, F. W. "Aromatic Poly(ether imide oxadiazole)s." High Performance Polymers 4, no. 2 (April 1992): 73–80. http://dx.doi.org/10.1088/0954-0083/4/2/002.

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Two oxadiazole containing aromatic diamines were synthesized. The diamines were prepared by reaction of aminophenols with 2,5-bis(4-fluorophenyl)-4l3,4-oxadiazole in a polar aprotic solvent in the presence of potassium carbonate. Reaction of the resulting 2,5-bis(4-(aminophenoxy)phenyl)-1,3,4-oxadiazoles with dianhydrides gave a series of polymeric amic acids. Thermal treatment yielded poly(imide ether oxadazole) films which displayed good thermal stability, flexibility, and glass transition temperatures ranging from 241 to 344C. The dielectric constants of the films were characterized as a function of relative humidity.

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Hamciuc, Corneliu, Elena Hamciuc, and Maria Bruma. "Poly(1, 3, 4-Oxadiazole-Amide)s Containing Pendent Phenoxy Groups." High Performance Polymers 8, no. 4 (December 1996): 507–14. http://dx.doi.org/10.1088/0954-0083/8/4/003.

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A series of new poly(1, 3, 4-oxadiazole-amide)s have been synthesized by solution polycondensation of aromatic diamines containing preformed 1, 3, 4-oxadiazole rings with phenoxyterephthalic diacid chloride or by the reaction of the same diacid chloride with p-aminobenzhydrazide resulting in a polyhydrazide-amide which was cyclodehydrated to the corresponding oxadiazolic structure. The new polymers were soluble or partially soluble in polar amidic solvents, were stable up to 375–400 °C in air and had a glass transition temperature in the range of 225–272 °C.

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Nguyen Tien, Cong, Duc Tran Thi Cam, Ha Bui Manh, and Dat Nguyen Dang. "Synthesis and Antibacterial Activity of Some Derivatives of 2-Methylbenzimidazole Containing 1,3,4-Oxadiazole or 1,2,4-Triazole Heterocycle." Journal of Chemistry 2016 (2016): 1–6. http://dx.doi.org/10.1155/2016/1507049.

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5-[(2-Methyl-1H-benzimidazol-1-yl)methyl]-1,3,4-oxadiazole-2-thiol or 5-[(2-methyl-1H-benzimidazol-1-yl)methyl]-4-(4-methylphenyl)-1,2,4-triazol-3-thiol which were prepared starting from 2-methylbenzimidazole in the reaction with appropriateN-aryl-2-chloroacetamides afforded two series ofN-aryl-2-{5-[(2-methyl-1H-benzimidazol-1-yl)methyl]-1,3,4-oxadiazol-2-yl}sulfanylacetamides andN-aryl-2-{5-[(2-methyl-1H-benzimidazol-1-yl)methyl]-4-(4-methylphenyl)-4H-1,2,4-triazol-3-ylthio}acetamides, respectively. The structures of the compounds were elucidated on the basis of IR, MS,1H-NMR, and13C-NMR spectral data. The compounds containing 1,3,4-oxadiazole or 1,2,4-triazole heterocycle also were tested for their antimicrobial activity against bacteria, mold, and yeast.

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Variya, Hiren H., Vikram Panchal, Falguni G. Bhabhor, and G. R. Patel. "Synthesis and Characterization of Biologically Potent Chalcone Bearing 1,3,4-Oxadiazole Linkage." International Letters of Chemistry, Physics and Astronomy 61 (November 2015): 77–83. http://dx.doi.org/10.18052/www.scipress.com/ilcpa.61.77.

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In this article, we have described to design and synthesized a series of substituted chalcone based 1,3,4-oxadiazole derivatives. Titled compounds (E)-S-(-5-phenyl-1,3,4-oxadiazol-2-yl) 2-(4-(3-(5-methyl-3oxo-2(p-tolyl)-2,3-dihydro-1H-pyrazol-4-yl)-3-oxoprop-1-en-1-yl) phenoxy) etanethioate (III1-6) were synthesized using of derivatives of S-(-5-phenyl-1,3,4 oxadiazole-2-yl)2-chloroethaethioate (I1-6) were reacted with (E)-4-(3-(4-hydroxyphenyl) acryloyl)-5-methyl-2(p-tolyl)-1H-pyrazol-3(2H)-one (II) in presence of K2CO3 in DMF as a solvent. The synthesized compounds were evaluated for their antimicrobial activity. The newly synthesized compounds were characterized by analytical and spectral (IR, 1H NMR, and LC-MS) Methods.

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Barbuceanu, Stefania-Felicia, Gabriela Laura Almajan, Ioana Saramet, Constantin Draghici, and Cristian Enache. "The Behaviour of Some Acylthiosemicarbazides in the Reaction with a-Halogenated Esters." Revista de Chimie 59, no. 3 (April 9, 2008): 304–8. http://dx.doi.org/10.37358/rc.08.3.1753.

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New six unexpected 1,3,4-oxadiazoles were obtained starting from acylthiosemicarbazides. N1-[4-(4-X-phenylsulfonyl)benzoyl]-N4-(2/3-methoxyphenyl)-thiosemicarbazides 2,3a-c were treated with ethyl chloro- or bromoacetate in presence of anhydrous sodium acetate in order to obtain new thiazolidin-4-ones compounds. However, formation of desired thiazolidin-4-ones from these acylthiosemicarbazides failed and instead 1,3,4-oxadiazoles were obtained. For confirmation presence of these compounds, 5-[4-(phenylsulfonyl)phenyl]-2-(3-methoxyphenylamino)-1,3,4-oxadiazole 5a was synthetized by cyclodesulfurization of acylthiosemicarbazide 3a with mercury (II) acetate. The structures of these compounds were elucidated by FTIR, UV, 1H-NMR and 13C-NMR, MS spectra and elemental analysis.

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Tauchman, Jiří, Jakub Trnka, Ivana Císařová, and Petr Štěpnička. "Synthesis, crystal structures and electrochemistry of ferrocenyl-substituted 1,3,4-oxadiazoles." Collection of Czechoslovak Chemical Communications 75, no. 10 (2010): 1023–40. http://dx.doi.org/10.1135/cccc2010064.

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Two ferrocenyl-substituted 1,3,4-oxadiazoles, 2-ferrocenyl-1,3,4-oxadiazole (1) and 2,5-diferrocenyl-1,3,4-oxadiazole (2), have been prepared from the corresponding hydrazides, (ferrocenecarbonyl)hydrazine (3) and 1,2-bis(ferrocenecarbonyl)hydrazine (4), and characterized by conventional spectroscopic methods (IR, NMR, MS) and elemental analyses. The solid-state structures of 1, 2 and 4 have been determined by single-crystal X-ray diffraction analysis. The redox behavior of 1 and 2 was studied by electrochemical methods. Compound 1 underwent a reversible one-electron oxidation attributed to the ferrocene/ ferrocenium couple (Eo′ = +0.28 V vs ferrocene/ferrocenium). On the other hand, compound 2 showed two closely separated anodic waves corresponding to two consecutive redox changes, indicating some degree of electronic communication between the ferrocenyl moieties in positions 2 and 5 at the 1,3,4-oxadiazole ring.

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22

Ribkovskaia, Zinaida, Serghei Pogrebnoi, Alic Barba, and Fliur Macaev. "Synthesis and Characterization of [(5-Mercapto-1,3,4-Oxadiazol-2-YL)Aryl]-3,5-Diaryl-4,5-Dihydro-1H-Pyrazole-1-Carbothioamides." Chemistry Journal of Moldova 6, no. 1 (June 2011): 90–100. http://dx.doi.org/10.19261/cjm.2011.06(1).04.

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The synthesis and characterization of [(5-mercapto-1,3,4-oxadiazol-2-yl)aryl]-3,5-diaryl-4,5-dihydro-1Hpyrazole-1-carbothioamides - derivatives of pyrazolines and 5-[4(3)-isothiocyanatophenyl]-2-thio-1,3,4-oxadiazoles were realized. The synthesized compounds, are crystalline substances, stable in storage and when exposed to air and light.

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23

Meng, Xingang, Niao Wang, Xiaofang Long, Lingzhu Chen, and Deyu Hu. "Qualitative and Quantitative Analysis of the New Sulfone Bactericide 2-(4-Fluorophenyl)-5-(Methylsulfonyl)-1,3,4-Oxadiazole and Identification of Its Degradation Pathways in Paddy Water." Journal of Chromatographic Science 58, no. 9 (August 22, 2020): 859–67. http://dx.doi.org/10.1093/chromsci/bmaa055.

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Abstract Rapid and simple methods for the determination of Jiahuangxianjunzuo (JHXJZ) in paddy water, brown rice, soil and rice straw was developed and validated. This method involved the use of ultrahigh-performance liquid chromatography equipped with photodiode array detector. The most important factor was chromatographic conditions, as identified through an orthogonal experimental design. This method showed good recoveries and precisions, thereby indicating its suitability for monitoring of JHXJZ residues in paddy water, brown rice, soil and rice straw. Furthermore, hydrolysis experiment was conducted in the laboratory under pH = 7 buffer solutions, and its degradation product was identified as 2-(4-fluorophenyl)-5-methoxy-1,3,4-oxadiazole by high-resolution mass spectrometry. JHXJZ has a major degradation pathway in the water which the OH− nucleophilic attack the C5 of 1,3,4-oxadiazole ring. Then it leaves mesyl to form intermediate 5-(4-fluorophenyl)-1,3,4-oxadiazol-2-ol and the intermediate combined with methanol formed the degradation product 2-(4-fluorophenyl)-5-methoxy-1,3,4-oxadiazole by the loss of one H2O.The degradation pathways of JHXJZ under the present indoor simulation conditions were proposed.

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Sattar, Almas, Aziz-ur-Rehman, Muhammad Athar Abbasi, Sabahat Zahra Siddiqui, Shahid Rasool, and Irshad Ahmad. "Synthesis of some novel enzyme inhibitors and antibacterial agents derived from 5-(1-(4-tosyl)piperidin-4-yl)-1,3,4-oxadiazol-2-thiol." Brazilian Journal of Pharmaceutical Sciences 52, no. 1 (March 2016): 77–85. http://dx.doi.org/10.1590/s1984-82502016000100009.

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ABSTRACT Keeping in mind the pharmacological importance of the 1,3,4-oxadiazole moiety, a series of new S-substituted derivatives, 5a-h, of 5-(1-(4-tosyl)piperidin-4-yl)-1,3,4-oxadiazol-2-thiol (3) were synthesized. The reaction of p-toluenesulfonyl chloride (a) and ethyl isonipecotate (b) produced ethyl 1-(4-tosyl)piperidin-4-carboxylate (1) which was further transformed into 1-(4-tosyl)piperidin-4-carbohydrazide (2) by hydrazine hydrate in methanol. Compound 2 was refluxed with CS2 in the presence of KOH to synthesize 5-(1-(4-tosyl)piperidin-4-yl)-1,3,4-oxadiazol-2-thiol (3). The desired compounds, 5a-h, were synthesized by stirring 3 with aralkyl halides, 4a-h, in DMF using NaH as an activator. The structures of synthesized compounds were elucidated by 1H-NMR, IR and EI-MS spectral studies. These compounds were further evaluated for enzyme inhibitory activity against lipoxygenase and alpha-glucosidase, along with antibacterial activity against Gram-negative and Gram-positive bacteria.

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Ahsan, Mohamed Jawed, Jyotika Sharma, Monika Singh, Surender Singh Jadav, and Sabina Yasmin. "Synthesis and Anticancer Activity ofN-Aryl-5-substituted-1,3,4-oxadiazol-2-amine Analogues." BioMed Research International 2014 (2014): 1–9. http://dx.doi.org/10.1155/2014/814984.

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In continuance of our search for anticancer agents, we report herein the synthesis and anticancer activity of some novel oxadiazole analogues. The compounds were screened for anticancer activity as per National Cancer Institute (NCI US) protocol on leukemia, melanoma, lung, colon, CNS, ovarian, renal, prostate, and breast cancers cell lines.N-(2,4-Dimethylphenyl)-5-(4-methoxyphenyl)-1,3,4-oxadiazol-2-amine (4s) showed maximum activity with mean growth percent (GP) of 62.61 and was found to be the most sensitive on MDA-MB-435 (melanoma), K-562 (leukemia), T-47D (breast cancer), and HCT-15 (colon cancer) cell lines with GP of 15.43, 18.22, 34.27, and 39.77, respectively. Maximum GP was observed on MDA-MB-435 (melanoma) cell line (GP=6.82) by compoundN-(2,4-dimethylphenyl)-5-(4-hydroxyphenyl)-1,3,4-oxadiazol-2-amine (4u).

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Kaya, Betül, Weiam Hussin, Leyla Yurttaş, Gülhan Turan-Zitouni, Hülya Gençer, Merve Baysal, Abdullah Karaduman, and Zafer Kaplancıklı. "Design and Synthesis of New 1,3,4-Oxadiazole – Benzothiazole and Hydrazone Derivatives as Promising Chemotherapeutic Agents." Drug Research 67, no. 05 (February 21, 2017): 275–82. http://dx.doi.org/10.1055/s-0042-119070.

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AbstractLooking for new cytotoxic and antimicrobial agents with improved antitumor activity, a series of hydrazide and oxadiazole derivatives were designed and synthesized using 3-methoxyphenol as starting substance. Novel N’-(arylidene)-2-(3-methoxyphenoxy)acetohydrazide derivatives (4a–f)/1-(4-substitutedphenyl)-2-[(5-[(3-methoxyphenoxy)methyl]-1,3,4-oxadiazol-2-yl)thio]ethan-1-one derivatives (6a–f)/N-(6-substitutedbenzothiazol-2-yl)-2-[(5-[(3-methoxyphenoxy)methyl]-1,3,4-oxadiazol-2-yl)thio]acetamide derivatives (7a–e) were obtained and evaluated for their in vitro antimicrobial activity against various gram-positive, gram-negative bacteria and fungi. The antimicrobial activity potential of the compounds against gram-negative bacteria was found to have higher compared to the potential against gram-positive bacteria. Also, compounds were screened for their antiproliferative activity against 2 selected human tumor cell lines, A549 lung, MCF7 breast cancer cell line and mouse embryo fibroblast cell line, NIH/3T3 as healthy cell line. Among the compounds evaluated, compound 7c bearing 1,3,4-oxadiazole ring and 6-methoxy benzothiazole moiety exhibited the highest inhibitory activity against A549 and MCF-7 tumor cell lines in contrary to NIH/3T3 cell line, as desired.

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Panchal, Ishan I., Roshani Rajput, and Ashish D. Patel. "Design, Synthesis and Pharmacological Evalution of 1,3,4-Oxadiazole Derivatives as Collapsin Response Mediator Protein 1 (CRMP 1) Inhibitors." Current Drug Discovery Technologies 17, no. 1 (April 17, 2020): 57–67. http://dx.doi.org/10.2174/1570163815666181106090708.

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Objective: The series of 2-(4-Phenylamino)-N-(5-((4-nitrophenoxy)methyl) -1,3,4-oxadiazol- 2-yl)aceta-mide (5a-5e) and substituted N-(5-(Phenoxymethyl)-1,3,4-oxadiazol-2-yl)-2- (phenylamino)acetamide (5f-5i) was designed, synthesized and investigated for Collapsin Response Mediator Protein 1 (CRMP 1) inhibitors as small lung cancer. Design: Design of compounds was determined by literature review and molecular docking studies in iGEMDOCK 2.0. Materials and Methods: Novel 1, 3, 4 Oxadiazole derivatives were synthesized and characterized by melting point, TLC, IR Spectroscopy, Mass spectroscopy and 1H NMR. In vitro biological evaluation was performed on NCI-H2066 cell line for different concentrations 10-1000μM by telomeric repeat amplification protocol assay. The assay of telomerase in cellular extracts was modified from the PCR-based Telomeric-Repeat Amplification Protocol (TRAP), using the oligonucleotides TS and CX. Results: Novel substituted 2-(4-Phenylamino)-N-(5-((4-nitrophenoxy)methyl)-1,3,4-oxadiazol-2- yl) acetamide (5a-5e) and substituted N-(5-(Phenoxymethyl)-1,3,4-oxadiazol-2-yl)-2-(phenylamino) acetamide (5f-5i) were synthesized, and characterized using spectral and analytical data. All compounds have shown considerable % inhibition of Cell Growth with respect to Bevacizumab, but compound 5a and 5f were equipotent with respect to activity as compared to standard Bevacizumab. Conclusion: Amongst the hybrids, p-nitro substituted derivative (5a) and p-chloro substituted (5f) showed the highest activity against human lung cancer cell line NCI-H2066 by TRAP assay.

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Patel, Navin, Sabir Pathan, and Hetal I. Soni. "3,4-Dihydropyrimidin-2(1H)-One Analogues: Microwave irradiated Synthesis with Antimicrobial and Antituberculosis Study." Current Microwave Chemistry 6, no. 1 (October 24, 2019): 61–70. http://dx.doi.org/10.2174/2213335606666190724093305.

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Background: For rapid and sustainable synthesis, microwave irradiation method is serviceable. This present study deals with the preparation of oxadiazole and pyridine bearing 1,2,3,4- tetrahydro pyrimidine derivatives by microwave irradiation. Objective: The present study aims to carry out rapid synthesis of chloro-acetamides of oxadiazoles of Biginelli product and amino cyano derivative of pyridine by microwave-assisted heating. Our efforts are focused on the introduction of chemical diversity in the molecular framework in order to synthesize pharmacologically interesting compounds. Methods:: Microwave irradiation was used for the synthesis of 2-((3-cyano-4-(3,4-dichloro phenyl)- 6-(4-hydroxy-3-methoxyphenyl) pyridin-2-yl) amino)-N-(5-(substituted) -(6-methyl-2-oxo -1,2,3,4- tetrahydro pyrimidin-5-yl)-1,3,4-oxadiazol-2-yl)acetamide by using Biginelli reaction. New structural analogues were confirmed by spectral studies followed by their screening for in vitro antibacterial activity against Staphylococcus aureus, Staphylococcus Pyogenus, Escherichia coli and Pseudomonas aeruginosa bacterial strains and for antifungal activity against Candida albicans, Aspergillus niger and Aspergillus clavatus by micro-broth dilution method. In vitro antimycobacterial activity determined out against (Mycobacterium tuberculosis) H37Rv strain using Lowenstein-Jensen medium. Results: As compared to the conventional method, microwave irradiation method is advantageous for the synthesis of 1,2,3,4-tetrahydropyrimidin derivatives. Potent antimicrobial activities and antitubercular activity were found for some of the compounds. Conclusion: Microwave irradiation method provided an effective way to discover a novel class of antimicrobial and antituberculosis agents. 1,2,3,4-tetrahydropyrimidin derivatives showed improved antimicrobial and good antituberculosis activity.

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J Khairnar, Bhikan, Rahul S. Salunke, Premchand B. Patil, Sanjay A. Patil, Rajeshwar J. Kapade, Pravin S. Girase, and Bhata R. Chaudhari. "Synthesis and Antimicrobial Activity of Some New 1, 4-Benzothiazine Containing Thiosemicarbazides and 1, 3, 4-Oxadiazole Derivatives." E-Journal of Chemistry 9, no. 1 (2012): 318–22. http://dx.doi.org/10.1155/2012/902784.

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A series of novel 3- methyl-7-substituted-4H,4-benzothiazine-2-carbohydrazide (3a-e) and corresponding thiosemicarbazides (4-a-q); 2-[3-methyl-7-substituted- 4H-1, 4-benzothiazine-2-yl]-N-(aryl) hydrazine carbothiamide have been synthesized. The thiosemicarbazide when cyclized with iodine via intramolecular cyclisation gave benzothiazonyl oxadiazoles (5-a-q); 5-(3-methyl -7-substitued-4H- 1,4-benzothiazin-2-yl)-N—aryl- 1,3,4- oxadiazol -2-amine and the compounds were tested for antibacterial and antifungal activities against different microorganisms.

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Das, Rina, and Dinesh Kumar Mehta. "Evaluation and Docking Study of Pyrazine Containing 1, 3, 4-Oxadiazoles Clubbed with Substituted Azetidin-2-one: A New Class of Potential Antimicrobial and Antitubercular." Drug Research 71, no. 01 (October 7, 2020): 26–35. http://dx.doi.org/10.1055/a-1252-2378.

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Abstract Background Tuberculosis (TB) caused by Mycobacterium tuberculosis is one of the main killers of people all over the world. The major hurdles with existing therapy are the lengthy regimen and appearance of multi drug resistant (MDR) and extensively drug resistant (XDR) strains of M.tuberculosis. Aims The present work was aimed to synthesize and determine antitubercular and antimicrobial potential of some novel 3-chloro-4-aryl-1-[4-(5-pyrazin-2-yl[1,3,4]oxadiazole-2-ylmethoxy)-phenyl]-azetidin-2-one derivatives 7(a-h) from pyrazinoic acid as precursor, which is a well-established antitubercular agent. Here we report the synthesis of a new class of heterocyclic molecules in which pyrazine, 1, 3, 4-oxadiazole and azetidinone moieties were present in one frame work. Methods Pyrazinoic acid (1) was esterified first (2) followed by amination to produce hydrazide (3) which was refluxed with POCl3 to obtain 2-chloromethyl-5pyrazino-1, 3, 4-oxadiazole (4). This was then further reacted with 4-amino phenol to obtain 4-[5-pyrazino-1, 3, 4-oxadiazol-2-yl-methoxy]-phenyl amine (5) which on condensation with various aromatic aldehydes afforded a series Schiff’s bases 6(a-h). Dehydrative annulations of 6(a-h) in the presence of chloroacetyl chloride and triethylamine yielded 3-chloro-4-aryl-1-[4-(5-pyrazin-2-yl-[1, 3, 4]oxadiazole-2-ylmethoxy)-phenyl]-azetidin-2-one derivatives 7(a-h). Antibacterial, antifungal and antitubercular potential of all the synthesized compounds were assessed. Docking study was performed using the software VLife Engine tools of Vlifemds 4.6 on the protein lumazine synthase of M. tuberculosis (PDB entry code 2C92). Results The present studies demonstrated that synthesized oxadiazole derivatives have good antimicrobial activity against the various microorganisms. Among the synthesized derivative, 7b and 7g were found to be prominent compounds which have potential antibacterial, antifungal and antitubercular activity (with MIC 3.12 µg/ml and high dock score ranging from −59.0 to −54.0) against Mycobacterium tuberculosis. Conclusions Derivatives 7b and 7g would be effective lead candidates for tuberculosis therapy.

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El-Sayed, Wael A., Farag A. El-Essawy, Omar M. Ali, Barsis S. Nasr, Mohamed M. Abdalla, and Adel A. H. Abdel-Rahman. "Anti-HIV Activity of New Substituted 1,3,4-Oxadiazole Derivatives and their Acyclic Nucleoside Analogues." Zeitschrift für Naturforschung C 64, no. 11-12 (December 1, 2009): 773–78. http://dx.doi.org/10.1515/znc-2009-11-1203.

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A number of new 5-[(naphthalen-5-yloxy)methyl]-1,3,4-oxadiazole derivatives, 2 - 5 and 8 - 11, were synthesized. The 2-{5-[(naphthalen-5-yloxy)methyl]-1,3,4-oxadiazol-2-ylthio}acetohydrazones 6a and 6b were synthesized by the reaction of the hydrazide 4 with the corresponding monosaccharides. Cyclization of the sugar hydrazones 6a and 6b with acetic anhydride afforded the substituted oxadiazoline derivatives 7a and 7b. The synthesized compounds were evaluated for their antiviral activity against, the human immunodefi ciency virus (HIV-1) and some of these compounds showed moderate to high antiviral activity.

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Xiao, Qiaobin, Sergei Vakulenko, Mayland Chang, and Shahriar Mobashery. "Mutations inmmpLand in the Cell Wall Stress Stimulon Contribute to Resistance to Oxadiazole Antibiotics in Methicillin-Resistant Staphylococcus aureus." Antimicrobial Agents and Chemotherapy 58, no. 10 (July 21, 2014): 5841–47. http://dx.doi.org/10.1128/aac.03501-14.

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ABSTRACTStaphylococcus aureusis a leading cause of hospital- and community-acquired infections, which exhibit broad resistance to various antibiotics. We recently disclosed the discovery of the oxadiazole class of antibiotics, which hasin vitroandin vivoactivities against methicillin-resistantS. aureus(MRSA). We report herein that MmpL, a putative member of the resistance, nodulation, and cell division (RND) family of proteins, contributes to oxadiazole resistance in theS. aureusstrain COL. Through serial passages, we generated twoS. aureusCOL variants that showed diminished susceptibilities to an oxadiazole antibiotic. The MICs for the oxadiazole against one strain (designatedS. aureusCOLI) increased reproducibly 2-fold (to 4 μg/ml), while against the other strain (S. aureusCOLR), they increased >4-fold (to >8 μg/ml, the limit of solubility). The COLRstrain was derived from the COLIstrain. Whole-genome sequencing revealed 31 mutations inS. aureusCOLR, of which 29 were shared with COLI. Consistent with our previous finding that oxadiazole antibiotics inhibit cell wall biosynthesis, we found 13 mutations that occurred either in structural genes or in promoters of the genes of the cell wall stress stimulon. Two unique mutations inS. aureusCOLRwere substitutions in two genes that encode the putative thioredoxin (SACOL1794) and MmpL (SACOL2566). A role formmpLin resistance to oxadiazoles was discerned from gene deletion and complementation experiments. To our knowledge, this is the first report that a cell wall-acting antibiotic selects for mutations in the cell wall stress stimulon and the first to implicate MmpL in resistance to antibiotics inS. aureus.

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Ahsan, Mohamed Jawed, Lakshya Bhandari, Shally Makkar, Rajan Singh, Mohd Zaheen Hassan, Mohammed H. Geesi, Mohamed Afroz Bakht, et al. "Synthesis, Antiproliferative, and Antioxidant Activities of Substituted N-[(1,3,4-Oxadiazol-2-yl) Methyl] Benzamines." Letters in Drug Design & Discovery 17, no. 2 (February 13, 2020): 145–54. http://dx.doi.org/10.2174/1570180816666181113110033.

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Background: Oxadiazole emerged as an important class of heterocyclic compound with diverse biological activities like anticancer, antitubercular, anticonvulsant, anti-tubulin, antimicrobial, anti-inflammatory, antioxidant etc. Objective: The objective of this study is to synthesis series of twelve substituted N-[(1,3,4-oxadiazol-2- yl)methyl]benzamines (6a-l) and their evaluation as antiproliferative and antioxidant agents. Methods: The substituted N-[(1,3,4-oxadiazol-2-yl)methyl]benzamines (6a-l) analogues were synthesized as per the reported procedure. The antiproliferative activity was tested against nine different panels cancer cell lines (leukemia, colon, renal, non-small cell lung, breast, CNS, melanoma, prostate, and ovarian cancer) at 10 µM drug concentrations as per the NCI US Protocol. Results: 2-(5-((3-Chloro-4-fluorophenylamino)methyl)-1,3,4-oxadiazol-2-yl)phenol (6e) revealed the significant antiproliferative activity among the series of title compounds (6a-l). The compound, 6e showed maximum sensitivity towards CCRF-CEM, MCF-7, MOLT-4, T-47D, and SR cell lines with percent growth inhibitions (%GIs) of 79.92, 56.67, 39.62, 34.71 and 33.35, respectively. Furthermore, the compounds, 6e and 6c showed promising antioxidant activity with an IC50 value of 15.09 and 19.02 µM, respectively in DPPH free radicals (FR) scavenging activity.R Conclusion: The present study may support a significant value in cancer drug discovery programme.

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S. Ahmed, Wurood, Ammar A. Razzak Mahmood, and Redha I. Al-Bayati. "Synthesis and Evaluation of Antimicrobial Activity of New Imides and Schiff Bases Derived from Ethyl -4-Amino Benzoate." Oriental Journal of Chemistry 34, no. 5 (October 19, 2018): 2477–86. http://dx.doi.org/10.13005/ojc/340533.

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A series of disubstituted 1,3,4-oxadiazole derivatives, including imides and Schiff bases, was achieved from the starting material, ethyl-4-aminobenzoate, which was converted to the corresponding 4-aminobenzohydrazide (1), by its reaction with hydrazine hydrate in absolute ethanol. Two oxadiazole parent nuclei had been synthesized from (1), the first nucleus 5-(4-aminophenyl)-1,3,4-oxadiazol-2-amine(2), and the second is 5-(4-aminophenyl)-1,3,4-oxadiazole-2-thione (3). Compound (2) Obtained from stirring methanolic solution of (1) with cyanogen bromide (CNBr) and sodium bicarbonate (NaHCO3) at RT. While compound (3) was synthesized by refluxing of (1) with CS2 in the presence of (KOH), the produced potassium salt of hydrazide underwent cyclization by acidification with 10% HCl. Meanwhile, the cyclic imides derivatives (4-6) and (10-12) were synthesized by thermal fusion of (2) or (3) with acid anhydrides, While Schiffʼs bases derivatives (7-9) and (13-15) were synthesized by a conventional method involved refluxing of (2) or (3) with different aromatic aldehydes, in acidic medium (using glacial acetic acid). The new derivatives had been tested against three Gram-positive bacteria (Staphylococcus aureus, Micrococcus luteus, and Bacillus pumilus), and two Gram-negative bacteria (Pseudomonas aeruginosa and Escherichia coli),and two fungal species: (Saccharomyces cerevisiae and Candida albicans). Among the synthesized derivatives, compound (15) displayed a moderate to potent antibacterial activity, against different (Gram- positive and Gram- negative) bacteria, and also showed a slight to moderate antifungal activity.

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Yamuna, Thammarse S., Jerry P. Jasinski, Brian J. Anderson, H. S. Yathirajan, and Manpreet Kaur. "Raltegravir monohydrate." Acta Crystallographica Section E Structure Reports Online 69, no. 12 (November 6, 2013): o1743—o1744. http://dx.doi.org/10.1107/s1600536813029747.

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The hydrated title compound [systematic name:N-(4-fluorobenzyl)-5-hydroxy-1-methyl-2-{1-methyl-1-[(5-methyl-1,3,4-oxadiazol-2-ylcarbonyl)amino]ethyl}-6-oxo-1,6-dihydropyrimidine-4-carboxamide monohydrate], C20H21FN6O5·H2O, is recognised as the first HIV integrase inhibitor. In the molecule, the dihedral angles between the mean planes of the pyrimidine ring and the phenyl and oxadiazole rings are 72.0 (1) and 61.8 (3)°, respectively. The mean plane of the oxadiazole ring is twisted by 15.6 (3)° from that of the benzene ring, while the mean plane of amide group bound to the oxadiaole ring is twisted by 18.8 (3)° from its mean plane. Intramolecular O—H...O and C—H...N hydrogen bonds are observed in the molecule. The crystal packing features O—H...O hydrogen bonds, which include bifurcated O—H...(O,O) hydrogen bonds from one H atom of the water molecule. In addition, N—H...O hydrogen bonds are observed involving the two amide groups. These interactions link the molecules into chains along [010].

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Wang, Lei, Yu-Ran Wu, Shu-Ting Ren, Long Yin, Xiu-Jian Liu, Feng-Chang Cheng, Wei-Wei Liu, Da-Hua Shi, Zhi-Ling Cao, and Hui-Min Sun. "Synthesis and bioactivity of novel C2-glycosyl oxadiazole derivatives as acetylcholinesterase inhibitors." Heterocyclic Communications 24, no. 6 (December 19, 2018): 333–38. http://dx.doi.org/10.1515/hc-2018-0166.

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Abstract A series of glycosyl-substituted 1,3,4-oxadiazoles were synthesized by cyclization of glycosyl-acylthiosemicarbazides via a base-catalyzed reaction. The starting glycosyl-acylthiosemicarbazide derivatives were obtained by the reaction of glycosyl isothiocyanate with various hydrazides. The acetylcholinesterase (AChE) inhibitory activities of the products were tested by Ellman’s method. The most active compounds were subsequently evaluated for the 50% inhibitory concentration (IC50) values. N-(1,3,4,6-tetra-O-benzyl-2-deoxy-β-D-glucopyranosyl)-5-(4-fluorophenyl)-1,3,4-oxadiazole-2-amine (6i) possesses the best AChE -inhibition activity with an IC50 of 1.61±0.34 μm.

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Sindhu, Jayant, Harjinder Singh, Jitender Mohan Khurana, Chetan Sharma, and Kamal Rai Aneja. "Multicomponent Synthesis of Novel 2-Aryl-5-((1-aryl-1H-1,2,3-triazol-4-yl)methylthio)-1,3,4-oxadiazoles using CuI as Catalyst and their Antimicrobial Evaluation." Australian Journal of Chemistry 66, no. 6 (2013): 710. http://dx.doi.org/10.1071/ch13082.

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A series of novel 2-aryl-5-((1-aryl-1H-1,2,3-triazol-4-yl)methylthio)-1,3,4-oxadiazoles have been synthesised by C–S bond formation and azide–alkyne cyclocondensation between [5-(aryl)-[1,3,4]oxadiazol-2-yl]methanethiol, propargyl bromide, and substituted aryl azides in one pot with an aim to explore their effect on the in vitro growth of microorganisms causing microbial infection. In vitro antibacterial activity was determined against four strains, namely Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa and antifungal activity against two fungal strains, namely Aspergillus niger and Aspergillus flavus.

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38

Gaonkar, Santosh L., Izuru Nagashima, and Hiroki Shimizu. "Microwave-Assisted Solution Phase Synthesis of Novel 2-{4-[2-(N-Methyl-2-pyridylamino)ethoxy]phenyl}-5-Substituted 1,3,4-Oxadiazole Library." Organic Chemistry International 2011 (January 3, 2011): 1–5. http://dx.doi.org/10.1155/2011/751894.

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A new series of 2-{4-[2-(N-methyl-2-pyridylamino)ethoxy]phenyl}-5-substituted 1,3,4-oxadiazoles were synthesized by the oxidative cyclization of hydrazones derived from 4-[2-(methylpyridin-2-ylamino)ethoxy]benzaldehyde and aryl hydrazines using chloramine-T as an efficient catalyst. All steps were assisted by microwave irradiation. Microwave enables all these reactions to be simple, rapid, high yielding, and avoid chromatograph purification and led environmentally benign total synthesis of focused oxadiazole library. All the synthesized compounds were isolated in good yield and characterized by 1H NMR, 13C NMR, and elemental analyses. The title compounds represent a novel class of biologically active heterocycles.

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Szafrański, Krzysztof, Jarosław Sławiński, Łukasz Tomorowicz, and Anna Kawiak. "Synthesis, Anticancer Evaluation and Structure-Activity Analysis of Novel (E)- 5-(2-Arylvinyl)-1,3,4-oxadiazol-2-yl)benzenesulfonamides." International Journal of Molecular Sciences 21, no. 6 (March 23, 2020): 2235. http://dx.doi.org/10.3390/ijms21062235.

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To learn more about the structure–activity relationships of (E)-3-(5-styryl-1,3,4-oxadiazol-2-yl)benzenesulfonamide derivatives, which in our previous research displayed promising in vitro anticancer activity, we have synthesized a group of novel (E)-5-[(5-(2-arylvinyl)-1,3,4-oxadiazol-2-yl)]-4-chloro-2-R1-benzenesulfonamides 7–36 as well as (E)-4-[5-styryl1,3,4-oxadiazol-2-yl]benzenesulfonamides 47–50 and (E)-2-(2,4-dichlorophenyl)-5-(2-arylvinyl)-1,3,4-oxadiazols 51–55. All target derivatives were evaluated for their anticancer activity on HeLa, HCT-116, and MCF-7 human tumor cell lines. The obtained results were analyzed in order to explain the influence of a structure of the 2-aryl-vinyl substituent and benzenesulfonamide scaffold on the anti-tumor activity. Compound 31, bearing 5-nitrothiophene moiety, exhibited the most potent anticancer activity against the HCT-116, MCF-7, and HeLa cell lines, with IC50 values of 0.5, 4, and 4.5 µM, respectively. Analysis of structure-activity relationship showed significant differences in activity depending on the substituent in position 3 of the benzenesulfonamide ring and indicated as the optimal meta position of the sulfonamide moiety relative to the oxadizole ring. In the next stage, chemometric analysis was performed basing on a set of computed molecular descriptors. Hierarchical cluster analysis was used to examine the internal structure of the obtained data and the quantitative structure–activity relationship (QSAR) analysis with multiple linear regression (MLR) method allowed for finding statistically significant models for predicting activity towards all three cancer cell lines.

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40

Anokhina, P. V., T. V. Romanova, S. F. Mel’nikova, and I. V. Tselinskii. "Reduction of 3,4-bis(4-amino-1,2,5-oxadiazol-3-yl)-1,2,5-oxadiazole 2-oxide." Russian Journal of Organic Chemistry 47, no. 10 (October 2011): 1606–7. http://dx.doi.org/10.1134/s1070428011100319.

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Fallon, Gary D., Craig L. Francis, Katarina Johansson, Andris J. Liepa, and Ruth C. J. Woodgate. "N,N-Dialkyl-N´-Chlorosulfonylchloroformamidines in Heterocyclic Synthesis. II. Thiazolo-, Thiadiazolo-, and Oxadiazolo-Fused [1,2,4,6]Thiatriazine Dioxides." Australian Journal of Chemistry 58, no. 12 (2005): 891. http://dx.doi.org/10.1071/ch05070.

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N,N-dialkyl-N′-chlorosulfonylchloroformamidines 1 were treated with 2-aminothiazoline, 2-aminothiazoles, 2-aminobenzothiazoles, 2-amino-1,3,4-thiadiazoles, and 2-amino-1,3,4-oxadiazoles to give a 6,7-dihydrothiazolo[3,2-b][1,2,4,6]thiatriazine dioxide 3, a 6,7-dihydrothiazolo[2,3-c][1,2,4,6]thiatriazine dioxide 4, thiazolo[3,2-b][1,2,4,6]thiatriazine dioxides 5, [1,2,4,6]thiatriazino[3,2-b]benzothiazole dioxides 7, a [1,2,4,6]thiatriazino[3,4-b]benzothiazole dioxide 8, [1,3,4]thiadiazolo[2,3-c][1,2,4,6]thiatriazine dioxides 10, [1,3,4]thiadiazolo[3,2-b][1,2,4,6]thiatriazine dioxides 11, [1,3,4]oxadiazolo[2,3-c][1,2,4,6]thiatriazine dioxides 13, and [1,3,4]thiadiazolo[3,2-b][1,2,4,6]thiatriazine dioxides 14. Compounds 3, 4, 5, 7, 8, 10, 11, 13, and 14 are derivatives of new ring systems.

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42

Epishina, M. A., A. S. Kulikov, and N. N. Makhova. "Synthesis of macrocyclic systems from 4,4′-diamino-3,3′-bi-1,2,5-oxadiazole and 3(4)-amino-4(3)-(4-amino-1,2,5-oxadiazol-3-yl)-1,2,5-oxadiazole 2-oxides." Russian Chemical Bulletin 57, no. 3 (March 2008): 644–51. http://dx.doi.org/10.1007/s11172-008-0101-0.

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Almalki, Abdulraheem S. A., Syed Nazreen, Azizah M. Malebari, Nada M. Ali, Ahmed A. Elhenawy, Abdullah A. A. Alghamdi, Abrar Ahmad, Sulaiman Y. M. Alfaifi, Meshari A. Alsharif, and Mohammad Mahboob Alam. "Synthesis and Biological Evaluation of 1,2,3-Triazole Tethered Thymol-1,3,4-Oxadiazole Derivatives as Anticancer and Antimicrobial Agents." Pharmaceuticals 14, no. 9 (August 28, 2021): 866. http://dx.doi.org/10.3390/ph14090866.

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A library of 1,2,3-triazole-incorporated thymol-1,3,4-oxadiazole derivatives (6–18) hasbeen synthesized and tested for anticancer and antimicrobial activities. Compounds 7, 8, 9, 10, and 11 exhibited significant antiproliferative activity. Among these active derivatives, compound 2-(4-((5-((2-isopropyl-5-methylphenoxy)methyl)-1,3,4-oxadiazol-2-ylthio)methyl)-1H-1,2,3-triazol-1-yl)phenol (9) was the best compound against all three tested cell lines, MCF-7 (IC50 1.1 μM), HCT-116 (IC50 2.6 μM), and HepG2 (IC50 1.4 μM). Compound 9 was found to be better than the standard drugs, doxorubicin and 5-fluorouracil. These compounds showed anticancer activity through thymidylate synthase inhibition as they displayed significant TS inhibitory activity with IC50 in the range 1.95–4.24 μM, whereas the standard drug, Pemetrexed, showed IC50 7.26 μM. The antimicrobial results showed that some of the compounds (6, 7, 9, 16, and 17) exhibited good inhibition on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The molecular docking and simulation studies supported the anticancer and antimicrobial data. It can be concluded that the synthesized 1,2,3-triazole tethered thymol-1,3,4-oxadiazole conjugates have both antiproliferative and antimicrobial potential.

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Kottakki, Naveen Kumar, Soujanya Kumari P V D, Gopi G, Amperayani Karteek Rao, and Devi Parimiuma. "SYNTHESIS AND ANTIBACTERIAL ACTIVITY OF PIPERAZINE ANALOGUES CONTAINING [1, 3, 4]-OXADIAZOLE RING." INDIAN DRUGS 57, no. 01 (January 28, 2020): 19–26. http://dx.doi.org/10.53879/id.57.01.12165.

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A new series of piperazine-1, 3, 4-oxadiazole deviatives were synthesized by the condensation of 1, 3, 4-thidaizole with substituted piperazine, in the presence of N, N-diisopropylethylamine. The structures were confirmed by IR, 1H NMR, 13C NMR and Mass spectroscopy. All the precursors were screened for anti-bacterial activity and the results indicate that phenyl substituted chloro (PO2) and hydroxy (PO6) functional derivatives possess better anti-bacterial activity towards to Gram-positive bacteria and gram-negative bacteria, Maximum zone of inhibition was observed in (PO2) against Bacillus subtillus (14.0 mm) and (PO6) against Pseudomonas aeruginosa (14.0 mm). Piperazine-1, 3, 4-oxadiazoles were synthesized by combining two active molecules into a new bioactive conjugate molecule. These new hybrid molecules have more potential biological activity than their parent molecules.

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Manojkumar, Parameswaran, Thengungal Ravi, and Gopalakrishnan Subbuchettiar. "Synthesis of coumarin heterocyclic derivatives with antioxidant activity and in vitro cytotoxic activity against tumour cells." Acta Pharmaceutica 59, no. 2 (June 1, 2009): 159–70. http://dx.doi.org/10.2478/v10007-009-0018-7.

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Synthesis of coumarin heterocyclic derivatives with antioxidant activity andin vitrocytotoxic activity against tumour cellsThe aim of the present work was to synthesise coumarinyl heterocycles and to elucidate the potential role of these compounds as antioxidants and cytotoxic agents against Dalton's lymphoma ascites tumour cells (DLA) and Ehrlich ascites carcinoma cells (EAC). The synthesis of coumarin derivatives containing pyrazole, pyrazolone, thiazolidin-4-one, 5-carboxymethyl-4-thiazolidinone and 3-acetyl-1,3,4-oxadiazole ring is reported. 4-Methylcoumarinyl-7-oxyacetic acid hydrazide (1) reacted with arylazopropanes or hydrazono-3-oxobutyrate derivatives to form pyrazole (3a-c) and pyrazolone derivatives (5a-c). Heterocyclisation of Schiff's bases of 1 with thioglycolic acid, thiomalic acid or acetic anhydride afforded novel heterocyclic derivatives 4-thiazolidinones (7a-c), 5-carboxymethyl-4-thiazolidinones (8a-c) and oxadiazoles (9a-c), respectively. Some of the compounds showed promising antioxidant activityin vitroand cytotoxic activity against DLA cells and EAC cells.

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Et al., Khammas. "Synthesis, Cytotoxicity, Xanthine Oxidase Inhibition, Antioxidant of New Pyrazolo{3,4 d}Pyrimidine Derivatives." Baghdad Science Journal 16, no. 4(Suppl.) (December 18, 2019): 1003. http://dx.doi.org/10.21123/bsj.2019.16.4(suppl.).1003.

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Allopurinol derivative were prepared by reacting the (1-chloroacetyl)-2-Hydropyrazolo{3,4-d}pyrimidine-4-oneiwith 5- methoxy- 2-aminoibenzothiazoleiunder certain conditions to obtain new compound ( N- (2-aminoacetyl (5-methoxy) benzothiazole -2yl) (A4), Reaction of 5-(P-dimethyl amine benzene)-2-amino-1,3,4- oxadiazole in the presence of potassium carbonate anhydrous to yield new compound (N-(2- aminoacetyl-5-(P-dimethyl amine benzene )-1,3,4-oxadiazoles-2-yl)(A30) and Azo compound (N-(5-(Azo-2-hydroxy-5-amino benzene)-1,3-Diazol-2yl)Allopurinol(A46). The structure of prepared compounds were confirmed by (FT-IR) technique and their physical properties. The synthesized compounds were tested for cytotoxicity, Xanthine oxidase inhibition, and antioxidant activity.

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Annam, Sri Charitha, K. V. Padmavathi, N. Murali Krishna, and Mannam Subbarao. "Computational Designing of Low Energy Band Gap of New Donor-Acceptor (D-A) Copolymer Monomers for Organic Solar Cells: DFT and TD-DFT Study." Science & Technology Journal 8, no. 2 (July 1, 2020): 44–54. http://dx.doi.org/10.22232/stj.2020.08.02.08.

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Via this look at efforts have been made to increase a chain of latest donor-acceptor (D-A) systems through the usage of 4-methoxy-2,7,nine-trimethyl-9H-carbazole (2,7-MMCB) as a electron donor and benzo[c][1,2,5] oxadiazole (BCO); benzo[c] [1,2,5] thiadiazole (BCT); benzo[c][1,2,5]selenadiazole (BCS); [1,2,5]oxadiazolo[3,4-c]pyridine (OCP); [1,2,5] thiadiazolo [3,4-c]pyridine (TCP); [1,2,5] selenadiazolo [3,4-c]pyridine (SCP); [1,2,5] oxadiazolo[3,4-d]pyridazine (ODP); [1,2,5] thiadiazolo[3,4-d]pyridazine (TDP) as electron acceptors. In this work, we executed calculations of DFT and TD-DFT/B3LYPmethod with /6-31G basis. Calculated and explored theoretical expertise of the HOMO, LUMO oenergies, the band gap (Eg), and the open-circuit voltage (Voc) of the studied compounds. To take a look at the relationship between molecularstructure and optoelectronic properties, the consequences of the extraordinary acceptor effect on the geometries and optoelectronic residences of those substances were discussed. The outcomes acquired show how the digital residences can be modified with many lessons of acceptors through the substituent and suggest that 2,7MMCB-ODP, 2,7MM CB-TDP, and 2,7MM CB-SDP are these compounds as suitable candidates for optoelectronic packages in solar cells inclusive of BHJ.

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Jia, Si-Yuan, Bo-Zhou Wang, Xue-Zhong Fan, Ping Li, and Seik Weng Ng. "4-[4-(4-Amino-1,2,5-oxadiazol-3-yl)-1,2,5-oxadiazol-3-yl]-1,2,5-oxadiazol-3-amine." Acta Crystallographica Section E Structure Reports Online 68, no. 5 (April 28, 2012): o1573. http://dx.doi.org/10.1107/s1600536812017825.

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Li, Hai-Lin, Hong-Wei Wang, Ran-Zhe Lu, and Hai-Bo Wang. "2-(4-Chlorophenyl)-5-{3,4-dibutoxy-5-[5-(4-chlorophenyl)-1,3,4-oxadiazol-2-yl]thiophen-2-yl}-1,3,4-oxadiazole." Acta Crystallographica Section E Structure Reports Online 64, no. 12 (November 8, 2008): o2298. http://dx.doi.org/10.1107/s1600536808035848.

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Rasool, Shahid, Aziz-ur-Rehman, Muhammad Athar Abbasi, Sabahat Zahra Siddiqui, Syed Adnan Ali Shah, Sidra Hassan, and Irshad Ahmad. "Synthesis, Structural Elucidation, and Antibacterial Evaluation of Some New Molecules Derived from Coumarin, 1,3,4-Oxadiazole, and Acetamide." Organic Chemistry International 2016 (September 7, 2016): 1–10. http://dx.doi.org/10.1155/2016/8696817.

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Because of the reported biological activities of coumarin, 1,3,4-oxadiazole, and acetamides, some new compounds incorporating these moieties were synthesized and evaluated for their biological potential against Gram-positive and Gram-negative bacteria. In the present work, 4-chlororesorcinol (1) and ethyl acetoacetate (2) were mixed in a strong acidic medium to synthesize 6-chloro-7-hydroxy-4-methyl-2-oxo-2H-chromene (3) which was subjected to the intermolecular cyclization after consecutive three steps to synthesize 5-[(6-chloro-4-methyl-2-oxo-2H-chromen-7-yl)oxy]methyl-1,3,4-oxadiazol-2-thiol (6). A series of acetamoyl electrophiles, 8a–o, were synthesized from aralkyl/alkyl/aryl amines, 7a–o, in an aqueous basic medium. The final compounds, 9a–o, were synthesized by the reaction of compounds 6 and 8a–o in DMF/NaH. The synthesized compounds were structurally elucidated by spectral data analysis of IR, 1H-NMR, and EIMS. The most of the synthesized compounds remained moderate to excellent antibacterial agents. The molecules, 9e, 9j, and 9k, were the most efficient ones against all the five bacterial strains taken into account.

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Journal articles on the topic '4-oxadiazoly'

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