- Crystal structures of two substituted 2,5-diaryl-1,3,4-oxadiazoles
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The crystal structures of 2,5-di(4-pyridyl)-1,3,4-oxadiazole, I, and 2-(4-cyanophenyl)-5-(4-dimethylaminophenyl)-1,3,4-oxadiazole, II, were determined from single crystal data (I: monoclinic, C2/c (no. 15), a = 5.3129(9) ?, b = 12.142(3) ?, c = 16.771(3) ?, β = 93.41(2)°, Rall = 0.0774; II: triclinic, P1? (no. 2), a = 7.3908(12) ?, b = 8.7992(15) ?, c = 12.036(2) ?, α = 77.04(2)°, β = 89.29(2)°, γ = 87.58(2)°, Rall = 0.0552). In both structures the formation of stacks of the almost planar molecules is observed as known for other oxadiazoles. These compounds exhibit differences to other substituted 2,5-diaryl-1,3,4-oxadiazoles in the crystalline structure.
- Stockhause,Wickleder,Meyer,Orgzall,Schulz
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- Crystal engineering: A unique cyclic assembly of a 40 membered module composed from two alternating units each of benzenehexacarboxylic acid (mellitic acid, MA) and 2,5-bis-(4-pyridyl)-1,3,4-oxadiazole (4-BPO): Assembly of modules to macromolecules by intermolecular hydrogen bonding
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Individually prepared, equivalent amounts of 2,5-bis-(4-pyridyl)-1,3,4- oxadiazole (4-BPO) and benzenehexacarboxylic acid (mellitic acid, MA) when mixed, deposited long rods, whose X-ray structure showed a unique assembly of 40 membered planar modules composed from two alternating units each of MA and 4-BPO, rather than the anticipated helical profile. Several novel features of complexes of MA with organic molecules are seen here. In almost all cases the intermolecular hydrogen bonding between MA anions is so stable that the MA anions and the complementary cations lie in separate planes. This barrier is overcome in the present case. The basic module associates to form quartets by very simple hydrogen bonding of the carboxylic groups of MA. The quartet assembly is characterized by the rotation of the left hand pair compared to the right hand pair. The mode of the macromolecular assembly is clear, that is, they are layered in alternating planes. Space group: P21/c with a = 9.181(1) A, b = 9.624(1) A, c = 29.390(2) A, and β = 94.626(4)°. The modules are embedded in an extensively hydrogen bonded MA network. The assembly profile of MA and 4-BPO is unique and should be a harbinger for the design of novel functional assemblies. The 40-membered module mimics the self-assemblies of peptides and can be important in the design of "Haptens" from simple molecules.
- Karle, Isabella L.,Rajesh,Ranganathan, Subramania
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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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supporting information
p. 7071 - 7073
(2014/08/05)
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- Synthesis and antimycobacterial activity of 4-(5-substituted-1,3,4-oxadiazol-2-yl)pyridines
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4-(5-Substituted-1,3,4-oxadiazol-2-yl)pyridine derivatives 1-12 were synthesized and evaluated for their in vitro antimycobacterial activity. Some compounds showed an interesting activity against Mycobacterium tuberculosis H37Rv and five clinic
- Navarrete-Vazquez, Gabriel,Molina-Salinas, Gloria Maria,Duarte-Fajardo, Zetel Vahi,Vargas-Villarreal, Javier,Estrada-Soto, Samuel,Gonzalez-Salazar, Francisco,Hernandez-Nunez, Emanuel,Said-Fernandez, Salvador
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p. 5502 - 5508
(2008/03/14)
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- 2,5-SUBSTITUTED OXAZOLE DERIVATIVES AS PROTEIN KINASE INHIBITORS FOR THE TREATMENT OF CANCER
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Certain oxazole-based compounds exhibiting ATP-utilizing enzyme inhibitory activity, methods of using compounds exhibiting ATP-utilizing enzyme inhibitory activity, and compositions comprising compounds exhibiting ATP-utilizing enzyme inhibitory activity, are disclosed.
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Page/Page column 66; 68
(2010/11/29)
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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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p. 935 - 938
(2007/10/03)
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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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