Microwave-assisted efficient synthesis of azlactone derivatives using 2-aminopyridine-functionalized sphere SiO_2 nanoparticles as a reusable heterogeneous catalyst

摘要

In the present work,the highly efficient Erlenmeyer synthesis of azlactones catalyzed by 2-aminopyridine,supported on nano-sphere SiO_2 is reported.First,the silica nanoparticles were modified with triethoxysilylpropyl chloride and then 2-aminopyridine was attached to the support via covalent linkages.This new heterogenized catalyst was used for efficient microwave-assisted synthesis of azlactone derivatives with Ac_2O as a condensing agent under solvent-free conditions.The present method offers advantages including high yields,short reaction times and simple work-up.Also,the catalyst can be easily recycled and reused several times,which makes this method attractive,economic and environmentally-benign.