Design of 2-Carboxy-1-sulfopyridin-1-ium Chloride as an Efficient and Eco-friendly Catalyst for the One-pot Synthesis of Highly Functionalized Tetrahydropyridines

The preparation of [1,2,4]triazolo[1,5-a]pyrimidines catalyzed by Schiff base zinc(ii) complex supported on magnetite nanoparticles under mild conditions

Nano-[CuFe2O4@SiO2/propyl-1-(O-vanillinaldimine)][ZnCl2] was prepared by placing a Schiff base zinc(ii) complex on a magnetite core and fully characterized by various analyses such as FT-IR, FE-SEM, EDAX, SEM-coupled EDX, TGA, VSM and TEM. The complexes supported on silica-coated magnetite copper ferrite nanoparticles were used as a reusable catalyst for the synthesis of 5-methyl-N,7-diphenyl-4,7-dihydro-[1,2,4]triazolo[1,5-a] pyrimidine-6-carboxamides resulting in 40% to 96% yield in the reactions of various aldehydes, acetoacetanilide, and 3-amino-1,2,4-triazole at 60 °C under solvent-free conditions. The zinc complex can change its structure from tetrahedral to square planar and catalyze the reaction. Some products containing the benzyloxy moiety are new and have been reported for the first time.

Synthesis of Novel Pyrimido[4,5-b] Quinolines Containing Benzyloxy and 1,2,3-Triazole Moieties by DABCO as a Basic Catalyst

DABCO was used as a basic and inexpensive catalyst for the synthesis of some new benzyloxy pyrimido[4,5-b]quinoline derivatives and 1,2,3- triazole-fused pyrimido[4,5-b]quinolines by the one-pot multi-component reaction of various benzyloxy benzaldehydes or benzylic -1,2,3-triazol-4-yl-methoxy benzaldehydes with dimedone and 6-amino-1,3-dimethyluracil at 90 °C under the solvent-free condition.

Nano-[Fe3O4@SiO2/N-propyl-1-(thiophen-2-yl)ethanimine][ZnCl2] as a nano magnetite Schiff base complex and heterogeneous catalyst for the synthesis of pyrimido[4,5-b]quinolones

Nano-[Fe₃O₄@SiO₂/N-propyl-1-(thiophen-2-yl)ethanimine][ZnCl₂] as a nano magnetite Schiff base complex was designed and fully characterized by various analyses such as Fourier transform infrared spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), differential thermal gravimetric analysis (DTA), vibrating sample magnetometry (VSM), scanning electron microscopy (SEM), and transmission electron micrographs (TEM). The presented nano magnetite Schiff base complex was used as a heterogeneous catalyst for the synthesis of pyrimido[4,5-b]quinolones by the reaction of aryl aldehyde, dimedone and 6-amino-1,3-dimethyluracil in EtOH : H₂O (7 : 3) as a solvent at 60 °C.

Nano-[Fe₃O₄@SiO₂/N-propyl-1-(thiophen-2-yl)ethanimine][ZnCl₂] as a nano magnetite Schiff base complex was designed and successfully tested for the synthesis of pyrimido[4,5-b]quinolones.