Hexamethylenetetramine grafted layered double hydroxides as a novel and green heterogeneous ionic liquid catalyst for the synthesis of pyrido[2,3-d]pyrimidine derivatives

Abstract

In this research layered double hydroxides functionalized with (3r,5r,7r)-1-(3-(triethoxysilyl)propyl)-1,3,5,7-tetraazaadamantan-1-ium chloride (LDHs–TPTAACl) as a novel, green, efficient and recyclable heterogeneous ionic liquid were synthesized and characterized by various methods, such as FT-IR, TGA, SEM, EDX, TEM and XRD. The mentioned catalyst was applied as a new ionic liquid catalyst for the one-pot three-component synthesis of a new class of pyrido[2,3-d]pyrimidine derivatives through combination of aromatic aldehydes, 2,4-thiazolidinedione and N,N-dimethyl-6-amino uracil using water as solvent in high to excellent yield and short reaction times. The LDHs–TPTAACl catalyst could be simply recycled and reused up to five continuous runs with no substantial structural change and loss of activity.