Electrosynthesis and screening of novel 1,3,4-oxadiazoles as potent and selective antifungal agents
作者:Sushma Singh、Laxmi Kant Sharma、Apoorv Saraswat、Ibadur R. Siddiqui、Harbans K. Kehri、Rana K. Pal Singh
DOI:10.1039/c3ra21904f
日期:——
The electrochemical oxidation of aldehyde-N-aroylhydrazone has been studied in the presence of NaClO4 as supporting electrolyte in MeOH solution using cyclic voltammetry and controlled potential electrolysis. The results indicate that intramolecular cyclization of aldehyde-N-aroylhydrazone has been successfully performed at a platinum electrode in an undivided cell with good yields of the corresponding 1,3,4-oxadiazoles at ambient conditions. The reaction products were characterized by spectroscopic methods and a mechanism was deduced from voltammetry studies. The antifungal activity of the synthesized compounds was evaluated on Fusarium oxysporum, Alternaria solani, Candida albicans and Aspergillus niger. The results revealed that all the synthesized compounds have significant antifungal activity against the tested fungi. Among the synthesized derivatives 7b, 7d, 7g, 7h, 7i, 7j and 7r were found to be the most effective antifungal compounds.
Iodine-catalysed oxidative cyclisation of acylhydrazones to 2,5-substituted 1,3,4-oxadiazoles
作者:Ganesh Majji、Saroj Kumar Rout、Srimanta Guin、Anupal Gogoi、Bhisma K. Patel
DOI:10.1039/c3ra44897e
日期:——
An environmentally benign synthesis of 2,5-disubstituted 1,3,4-oxadiazoles has been developed starting from N-aroylhydrazones and N-acetylhydrazones at room or ambient temperature using a catalytic quantity of iodine in the presence of an aqueous hydrogen peroxide oxidant.
Efficient oxidative cyclization of <i>N</i>-acylhydrazones for the synthesis of 2,5-disubstituted 1,3,4-oxadiazoles using <i>t</i>-BuOI under neutral conditions
作者:Peng Gao、Yunyang Wei
DOI:10.1515/hc-2012-0179
日期:2013.4.1
in situ from t-BuOCl and NaI. A variety of 2,5-disubstituted1,3,4-oxadiazoles were synthesized in high yields within short reaction time. The method is also suitable for cyclization of N-acylhydrazones derived from heterocyclic aldehydes and aliphatic aldehydes. Mild reaction conditions and simple workup operations make the procedure a good alternative for the synthesis of 2,5-disubstituted 1,3,4-oxadiazoles
Electrochemical oxidation of aldehyde-N-arylhydrazones into symmetrical-2,5-disubstituted-1,3,4-oxadiazoles
作者:Sushma Singh、Laxmi K. Sharma、Apoorv Saraswat、Ibadur R. Siddiqui、Rana K. Pal Singh
DOI:10.1007/s11164-012-1013-z
日期:2014.3
A convenient, efficient and one-pot synthesis of chemically and pharmaceutically interesting symmetrical-2,5-disubstituted-1,3,4-oxadiazoles is reported. The protocol involves anodic oxidation of aldehyde-N-arylhydrazones in anhyd. MeCN–LiClO4. Constant potential electrolysis carried out in an undivided cell and platinum electrodes leads to the formation of the corresponding oxadiazoles under ambient condition and the mechanism was deduced from voltammetry studies. The reaction proceeded smoothly with high atom economy.
3-Acetyl-2,5-diaryl-2,3-dihydro-1,3,4-oxadiazoles were designed, synthesized, and tested as inhibitors against human monoamineoxidase (MAO) A and B isoforms. Several compounds, obtained as racemates, were identified as selective MAO-B inhibitors. The enantiomers of some derivatives were separated by enantioselective HPLC and tested. The R-enantiomers always showed the highest activity. Docking study