Copper(I) complex of 1,3‐DimethylBarbituric acid modified SBA‐15 and its catalytic role for the synthesis of 2,3‐Dihydroquinazolin‐4(1H)‐ones and Imidazoles

Abstract

An efficient one‐pot method for synthesis of 2,3‐dihydroquinazolin‐4(1H)‐ones and tri/tetra substituted‐1H‐imidazoles has been accomplished in the presence of catalytic amounts of Cu(I)‐1,3‐dimethylbarbituric acid modified SBA‐15 as heterogeneous catalyst with good to excellent yields. The catalyst is reusable and can be applied several times without any decrease in product yield. The synthesized catalyst was characterized by scanning electron microscopy (SEM), X‐ray diffraction (XRD), energy dispersive X‐ray spectroscopy (EDS), thermal gravimetric analysis (TGA), N2 adsorption/desorption isotherms (BET), Fourier transform infrared spectroscopy (FT‐IR) and atomic absorption spectroscopy (AAS).

Supported Metal Catalysts for the Synthesis of N-Heterocycles

“…In 2017, Hajjami and co-workers described the synthesis of a Cu(I)-1,3-dimethylbarbituric acid complex immobilized on mesoporous SBA-15 silica. First, SBA-15 was treated with 3-aminopropyltriethoxysilane in order to obtain the corresponding amino-functionalized material (SBA-15-n-Pr-NH 2 ); then, such material was added to a solution of 1,3-dimethylbarbituric acid in ethanol and refluxed for 48 h; finally, the SBA-15-anchored ligand was added to a solution of CuCl in acetonitrile and stirred for 24 h at room temperature, giving the final SBA-15-DMBA-Cu(I) catalyst [167]. Such a catalyst was then applied at low copper loading (0.7 mol%) to the one-pot synthesis of trisubstituted imidazoles 227 and tetrasubstituted imidazoles 228 under solvent-free conditions at 100 • C; the expected products were obtained in excellent yields and the SBA-15-DMBA-Cu(I) catalyst could be easily isolated and reused up to five times without a loss of activity (Scheme 70).…”

“…SBA-15-anchored ligand was added to a solution of CuCl in acetonitrile and stirred for 24 h at room temperature, giving the final SBA-15-DMBA-Cu(I) catalyst [167]. Such a catalyst was then applied at low copper loading (0.7 mol%) to the one-pot synthesis of trisubstituted imidazoles 227 and tetrasubstituted imidazoles 228 under solvent-free conditions at 100 °C; the expected products were obtained in excellent yields and the SBA-15-DMBA-Cu(I) catalyst could be easily isolated and reused up to five times without a loss of activity (Scheme 70).…”

CoFe2O4@SiO2‐CPTES‐Guanidine‐Cu(II): A novel and reusable nanocatalyst for the synthesis of 2,3‐dihydroquinazolin‐4(1H)‐ones and polyhydroquinolines and oxidation of sulfides

“…Quinazolines are an important category of nitrogen‐containing heterocyclic compounds which consist of fused benzene and pyrimidine rings . These compounds have significant biological activity such as antifungal, antitumour, vasodilatory, anticancer and antifibrilatory activities . Organosulfur compounds due to their various applications are known as interesting compounds in the pharmaceutical and chemical industries.…”

“…[15] These compounds have significant biological activity such as antifungal, antitumour, vasodilatory, anticancer and antifibrilatory activities. [16][17][18] Organosulfur compounds due to their various applications are known as interesting compounds in the pharmaceutical and chemical industries. Sulfoxides have very important structures because they contain S═O bonds and are privileged structural scaffolds for building pharmacologically and biologically active molecules as well as because of their unique properties, such as central chirality at the sulfur, high configurational stability and the strongly polarized S═O bond, which have attracted the attention of researchers.…”