- Antimicrobial studies of 2,4-dichloro-5-fluorophenyl containing oxadiazoles
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A series of 2,4-dichloro-5-fluorophenyl containing 1,3,4-oxadiazoles (10 and 11) were synthesized by POCl3 cyclization of 2,4-dichloro-5-fluorobenzoyl hydrazide (4) and 2-(2,4-dichloro-5-fluorophenyl)cinchoninyl hydrazide (8) with aryloxyacetic
- Karthikeyan, Mari Sithambaram,Prasad, Dasappa Jagadeesh,Mahalinga, Manjathuru,Holla, Bantwal Shivarama,Kumari, Nalilu Suchetha
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- Stereoselective synthesis and fungicidal activities of (E)-α- (methoxyimino)-benzeneacetate derivatives containing 1,3,4-oxadiazole ring
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Fifteen novel (E)-α-(methoxyimino)-benzeneacetate derivatives, the analogues of strobilurins, which contain two pharmacophoric substructures of (E)-methyl methoxyiminoacetate moiety and 1,3,4-oxadiazole ring were stereoselectively synthesized. It was first found that the coupling reaction could give stereoselectively the key intermediate (E) and (Z)-methyl 2-(hydroxyimino)-2-o-tolylacetate 2 with a ratio of 14:1. The preliminary bioassays indicated that all the compounds 1 showed potent fungicidal activity against Rhizoctonia solani, Botrytis cinereapers, Gibberella zeae, Physalospora piricola and Bipolaris mayclis, and all of the tested compounds 1a-1o had more potent fungicidal activities against R. solani than Kresoxim-methyl.
- Li, Yan,Liu, Jie,Zhang, Hongquan,Yang, Xiangping,Liu, Zhaojie
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p. 2278 - 2282
(2007/10/03)
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- Synthesis of some new fluorine containing 1,3,4-oxadiazole derivatives as potential antibacterial and anticancer agents
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The synthesis of a number of 1,3,4-oxadiazole derivatives have been described. 2,4-Dichloro-5-fluorobenzoyl hydrazine 1 on reacting with aromatic acids in presence of phosphorus oxychloride affords 2,5-disubstituted-1,3,4- oxadiazoles 2a-j. Aroyl hydrazine on reacting with carbon disulphide under basic condition gives oxadiazol-2-thione 3. Oxadiazol-2-thiones are regioselectively aminomethylated to give N-aminomethylated products 4a-c. Further, 3 undergoes regioselective alkylation on treating with alkyl/aroyl halides to give S-alkyl/aroyl products 5a-c. All the newly synthesized compounds have been screened for their antibacterial activity. Most of them show promising antibacterial activity. Also two out of nine compounds show anticancer activity in the primary anticancer assay.
- Bhat, K. Subrahmanya,Karthikeyan,Holla, B. Shivarama,Shetty, N. Suchetha
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p. 1765 - 1769
(2007/10/03)
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- Syntheses and insecticidal activities of novel 2,5-disubstituted 1,3,4-oxadiazoles
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Nine novel symmetrical and asymmetrical 2,5-disubstituted 1,3,4-oxadiazoles have been synthesized by a facile and mild method with high yield. Meantime, it was found that the fluorine was easy substituted by hydrazine in polyhalogen-substituted aroyl hydrazine. The preliminary bioassay tests show that two of the compounds (D5> and D6) exhibited a significant insecticidal activity (LC50=116.02 and 70.93 mg l-1) on armyworm, Leucania separata Walker. Using the Drug Discovery Workbench (DDW) (Cerius2), structure-activities relationship was studied.
- Zheng, Xiumian,Li, Zhong,Wang, Yanli,Chen, Weidong,Huang, Qingchun,Liu, Chuanxiang,Song, Gonghua
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p. 163 - 169
(2007/10/03)
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- Synthesis and antifeedant activity of new oxadiazolyl 3(2H)-pyridazinones
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A total of 20 new compounds containing the oxadiazolyl 3(2H)-pyridazinone moiety were synthesized. The structures of all the compounds were confirmed by 1H NMR, IR, MS, and elemental analysis. Their insect antifeedant activities against Asiatic corn borer Ostrinia furnacalis (Guenee) were examined and compared with commercial azadirachtin. The compounds exhibited significant levels of activity. The feeding deterrency values of IIIa,j were 57% and 51% at 500 mg/kg concentration, respectively.
- Cao, Song,Qian, Xuhong,Song, Gonghua,Chai, Bing,Jiang, Zhisheng
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p. 152 - 155
(2007/10/03)
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- Synthesis and insecticidal activity of neonicotinoids derivatives
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A new class of compounds- neonicotinoids containing oxadiazole -were synthesized and characterized by using 1H NMR, IR, MS and Elemental Analysis. Their insecticidal activities were tested against Mythimna separata Walker and Aphis rumicis Linnaeus, some of them showed some insecticidal activity.
- Chai, Bing,Cao, Song,Liu, Haidong,Song, Gonghua,Qian, Xuhong
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p. 601 - 606
(2007/10/03)
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- Syntheses and insecticidal activities of novel 2-fluorophenyl-5-aryl/cyclopropyl-1,3,4-oxadiazoles
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Two 2-fluorophenyl-5-substitued cyclopropyl-1,3,4-oxadiazoles (IIIa-b) with cis/trans isomers were synthesized from the corresponding hydrazide (Ia) and aroyl chlorides by two-step reactions. Six asymmetrical 2-(2,4-dichloro-5-fluorophenyl)-5-aryl-1,3,4-oxadiazoles (IIIc-h) were obtained by one step reaction of 2,4-dichloro-5-fluorobenzoic acid hydrazide (Ic) with the corresponding aromatic carboxylic acid in the presence of phosphorus oxychloride under reflux. However, the similar reaction of 4-fluorophenoxyacetic acid hydrazide (Ib) with 2,4-dichloro-5-fluorobenzoic acid failed to yield the desired asymmetrical 2-(2,4-dichloro-5-fluorophenyl)-5-(fluorophenoxymethyl)-1,3,4-oxadiazole, and the resulting product was characterized as symmetrical 2,5-bis(2,4-dichloro-5-fluorophenyl)-1,3,4-oxadiazole (DCFPO). A possible reaction mechanism is suggested. Insecticidal activities of these nine new compounds against armyworms (Pseudaletia separata Walker) were determined.
- Shi, Wei,Qian, Xuhong,Song, Gonghua,Zhang, Rong,Li, Rongpo
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p. 173 - 179
(2007/10/03)
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