One-pot synthesis of pyrano[3,2-c]quinoline-2,5-dione derivatives by Fe3O4@SiO2-SO3H as an efficient and reusable solid acid catalyst

Abstract

In this study, Fe 3 O 4 @SiO 2 -SO 3 H was prepared as an efficient and reusable solid acid catalyst and its catalytic activity was considered in the synthesis of pyrano[3,2-c]quinoline-2,5-dione derivatives by the threecomponent reaction of 4-hydroxyquinolin-2(1H)-one, Meldrum's acid and arylaldehydes under thermal solventfree conditions at 70°C. This catalytic system can be reused minimally for five times without any noticeable loss of activity. In addition, the characteristic analysis of Fe 3-O 4 @SiO 2 -SO 3 H, such as thermogravimetric analysis, Fourier-transform infrared spectroscopy, vibrating sample magnetometer, scanning electron microscope, and X-ray diffraction was performed. Graphical abstract

Synthesis of a Biological‐Based Glycoluril with Phosphorous Acid Tags as a New Nanostructured Catalyst: Application for the Synthesis of Novel Natural Henna‐Based Compounds

“…On the other hand, multicomponent reactions (MCRs) have become a very important tool in organic chemistry because three or more starting materials react to form a product, which all or most of the atoms contribute to the final product . This type of reactions have been widely used in the synthesis of complex pharmaceutically active heterocyclic compounds, especially nitrogen‐containing derivatives due to the biological activity usually shown by this type of compounds . Functionalized quinone‐ and naphthoquinone derivatives are molecules often obtained from natural sources (henna's leaves, Streptocapus dunnii,…) which have been widely used as synthetic intermediates in both academia and industry due to their interesting biological and drug‐like properties .…”