فهرست مقالات ultrasound irradiation

• دسترسی آزاد مقاله
  • صفحه چکیده
  • متن کامل
  
  1 - Citric acid as an efficient and green catalyst for the synthesis of hexabenzylhexaazaisowurtzitane (HBIW)
  Sahar Shokrollahi Ali Ramazani Seyed Jamal Tabatabaei Rezaei Asemeh Mashhadi Malekzadeh Pegah Azimzadeh Asiabi Sang Woo Joo
  The condensation of benzylamine with glyoxal leads to Hexabenzylhexaazaisowurtzitane (HBIW) in acetonitrile solvent with citric acid as a green catalyst under both conventional stirring and ultrasonic irradiation conditions. The influence of four variables, including th چکیده کامل

  The condensation of benzylamine with glyoxal leads to Hexabenzylhexaazaisowurtzitane (HBIW) in acetonitrile solvent with citric acid as a green catalyst under both conventional stirring and ultrasonic irradiation conditions. The influence of four variables, including the amount of catalyst, solvent, reaction time and ultrasonic power, on the reaction yield was investigated. The results showed that the optimum parameters for synthesis of HBIW were 5% mol with respect to glyoxal for catalyst, acetonitrile-water as solvent, 5 minutes as reaction time and 150 W for ultrasonic power. In general, improvement in rates and yields were observed when the reactions were carried out under sonication in comparison with classic conditions. پرونده مقاله
• دسترسی آزاد مقاله
  • صفحه چکیده
  • متن کامل
  
  2 - Graphene–ZnO@SiO2 hybrid: An efficient and solid acid catalyst for synthesis of azlactones under ultrasound irradiation
  Sodeh Sadjadi
  The central theme of this article is how to explore a novel route to fabricate graphene– ZnO@SiO2 hybrid by a covalent process. The synthesis procedure consists of three-steps: (1) synthesis of ZnO nanoparticles, (2) ZnO nanoparticles modification by tetraethyl or چکیده کامل

  The central theme of this article is how to explore a novel route to fabricate graphene– ZnO@SiO2 hybrid by a covalent process. The synthesis procedure consists of three-steps: (1) synthesis of ZnO nanoparticles, (2) ZnO nanoparticles modification by tetraethyl orthosilicate and (3-aminopropyl) triethoxysilane after introduction of amino groups on its surface, (3) the covalent attachment of ZnO@SiO2 onto the graphene surface by the amidation reaction between amino group of ZnO@SiO2 and carboxylic group of graphene. This hybrid was then used as a catalyst for the synthesis of azlactones obtained by Erlenmeyer synthesis from aromatic aldehydes and hippuric acid under the ultrasonic irradiation. The protocol offers advantages in terms of higher yields, short reaction times, mild reaction conditions, and reusability of the catalyst. پرونده مقاله
• دسترسی آزاد مقاله
  • صفحه چکیده
  • متن کامل
  
  3 - Magnetic Fe3O4 nanoparticles as a highly efficient catalyst for the synthesis of imidazoles under ultrasound irradiation
  Javad Safari Zohre Zarnegar
  To be fairly general and catalyst is easily separated by magnetic devices and can be reused without any apparent loss of activity for the reaction. Fe3O4 nanoparticles were prepared by chemical coprecipitation method and was found to be a mild and effective catalyst for چکیده کامل

  To be fairly general and catalyst is easily separated by magnetic devices and can be reused without any apparent loss of activity for the reaction. Fe3O4 nanoparticles were prepared by chemical coprecipitation method and was found to be a mild and effective catalyst for the efficient, one-pot, three-component synthesis of 2,4,5-trisubstituted imidazoles at room temperature under ultrasound irradiation. The high yields of products and short reaction time were attributed to the nanosize of about 20 nm in which the catalyst could act as a nanoreactor. This methodology is found. پرونده مقاله