21398-10-7Relevant articles and documents
IBX/KI promoted synthesis of 2, 5-disubstituted 1, 3, 4-oxadiazoles
Khan, P. Rasvan,Durgaprasad,Reddy, S. Gopal,Reddy, G. Raveendra,Hussein, Ibnelwaleed A.,Reddy, B.V. Subba
, p. 64 - 69 (2018/03/05)
Background: Oxadiazoles are privileged scaffolds in different areas of medicinal, pesticidal, polymer and material science. They act as anticancer, benzodiazepine receptor agonists, antimicrobial, analgesic, diuretic and tyrosinase inhibitors etc. A number of compounds containing an oxadiazole moiety are in late stage clinical trials including zibotentan and furamizole. Despite numerous methods are reported, the majority of them suffer from major drawbacks such as the use of strong alkaline or acidic conditions, highly toxic and corrosive reagents and also involve the use of costly reagents, elevated temperatures and longer reaction times. Inspired by the potential application of hypervalent iodonium reagents in organic synthesis, we would like to explore the readily available IBX and KI reagents for the facile synthesis of 1, 3, 4-oxadiazoles. Method: Oxidative cyclization has successfully been developed for the synthesis of 2, 5-disubstituted 1, 3, 4-oxadiazoles. Results: An efficient process for the one-pot synthesis of 2, 5-disubstituted 1, 3, 4-oxadiazoles has been developed using IBX/KI system at 25°C. The reaction was successful with a wide range of substrates such as aromatic and heterocyclic aldehyde and arylhydrazides to afford the corresponding unsymmetrical 2, 5-disubstituted 1, 3, 4-oxadiazoles. The mild reaction conditions, cost-effective reagents and short reaction time are noteworthy advantages of this methodology. Conclusion: We have developed a one-pot strategy for the synthesis of 1, 3, 4-oxadiazioles using a combination of IBX/KI at ambient temperature. This one-pot procedure proved to be quite general and worked well with a wide variety of aryl and heterocyclic aldehydes and variety of acylhydrazides. The advantage of this method lies in the simplicity of experimental procedure and the ready accessibility of the reagents, which render this, an experimentally attractive method for the preparation of unsymmetrical 1, 3, 4-oxadiazoles.
A process for preparing 2, 5 - disubstituted - 1, 3, 4 - oxadiazoles (by machine translation)
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Paragraph 0031; 0032; 0033; 0034; 0035; 0061-0065, (2017/07/19)
The invention provides a method for catalytic oxidative cyclization of formula (II) is shown in the 1, 3, 4 - oxadiazole method, said method comprising: in order to having a structure of formula (I) indicated by the formyl zong compound as a raw material, in order to air or oxygen atmosphere, in order to nitric acid the iron is catalyst, in order to 2, 2, 6, 6 - tetramethyl piperidine nitrogen oxides as initiator, under the action of the water absorbing agent, under the action of the water absorbing agent, in an organic solvent, for 25 - 60 °C lower reaction 3 - 12h, and the resulting reaction solution by the following formula (II) after treatment indicated by the 1, 3, 4 - oxadiazole compounds; the reaction of the invention speed, mild condition, easy operation, low cost, safe reaction, the whole process is friendly to the environment, pollution-free. (by machine translation)
2,5-Disubstituted-1,3,4-oxadiazoles: Thymidine phosphorylase inhibitors
Khan, Khalid Mohammed,Rani, Mubeen,Ambreen, Nida,Ali, Muhammad,Hussain, Sajjad,Perveen, Shahnaz,Choudhary, Muhammad Iqbal
, p. 6022 - 6028 (2013/11/06)
A series of 2,5-disubstituted-1,3,4-oxadiazoles (1-16) were synthesized via microwave irradiation and screened against thymidine phosphorylase enzyme. Four members of the series have demonstrated thymidine phosphorylase inhibitory activities with IC50 values between 37 and 320 μM. Pyridinyl-containing 1,3,4-oxadiazoles exhibited an enhanced inhibitory potential, while phenyl analogs did not show substantial inhibitory potential. Compound 9, a dipyridinyl residue having an IC50 value of 37 ± 0.76 μM was found to be the most potent in the series superior to standard inhibitor 7-deazaxanthine (IC50 = 39.28 ± 0.76 μM). Graphical abstract: [InlineMediaObject not available: see fulltext.]
