Synthesis of 5-aryl-3H-[1,3,4]oxadiazol-2-ones from N′-(chloro-aryl-methylene)-tert-butylcarbazates using basic alumina as an efficient and recyclable surface under solvent-free condition
摘要:
The synthesis of biologically important 5-aryl-3H-[1,3,4]oxadiazol-2-ones has been carried out by heating the easily synthesized N'-(chloro-aryl-methylene)-tert-butylcarbazates on basic alumina surface under solvent-free condition. The dual characteristic of basic alumina as a solid support as well as a nucleophile is successfully exploited in these reactions. The method provides special attributions such as reduced reaction times, easier work-up procedures, and good to excellent yields as well as increased purity of products and most importantly environmentally friendly protocols. The basic alumina is easily recovered and utilized for further reactions several times without serious loss of activity. (C) 2012 Elsevier Ltd. All rights reserved.
Synthesis of 5-aryl-3H-[1,3,4]oxadiazol-2-ones from N′-(chloro-aryl-methylene)-tert-butylcarbazates using basic alumina as an efficient and recyclable surface under solvent-free condition
摘要:
The synthesis of biologically important 5-aryl-3H-[1,3,4]oxadiazol-2-ones has been carried out by heating the easily synthesized N'-(chloro-aryl-methylene)-tert-butylcarbazates on basic alumina surface under solvent-free condition. The dual characteristic of basic alumina as a solid support as well as a nucleophile is successfully exploited in these reactions. The method provides special attributions such as reduced reaction times, easier work-up procedures, and good to excellent yields as well as increased purity of products and most importantly environmentally friendly protocols. The basic alumina is easily recovered and utilized for further reactions several times without serious loss of activity. (C) 2012 Elsevier Ltd. All rights reserved.
Facile synthesis of ninhydrin and isatin based hydrazones in water using PEG-OSO3H as a highly efficient and homogeneous polymeric acid-surfactant combined catalyst
The synthesis of a series of biologically important ninhydrin and isatin based hydrazones has been carried out by refluxing easily synthesized novel N'-(chloro-aryl-methylene)-tert-butylcarbazates with ninhydrin and isatins in the presence of PEG-OSO3H as catalyst in water medium. The dual characteristic of PEG-OSO3H as a Bronsted acid as well as a phase-transfer catalyst is successfully exploited in this synthesis. Reduced reaction time, operational simplicity, excellent yields of the products with high purity, and more importantly, easy recoverability, and reusability of the homogeneous polymeric catalyst make the reaction an attractive, economic, and sustainable green synthetic methodology. (C) 2013 Elsevier Ltd. All rights reserved.