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A green heterogeneous nanocatalyst, Cu(II)‐PBABMD complex immobilized on core‐shell magnetic γ‐Fe2O3@HAp, was successfully designed, synthesized, and characterized by FTIR, XRD, FESEM, EDX, VSM, TGA, BET, ICP‐OES, and TEM techniques. The magnetic Cu(II) nanocatalyst was employed as a novel, ecofriendly, recyclable, and safe catalyst for the one‐pot, three‐component condensation of 6‐amino‐2‐thioxo‐2,3‐dihydropyrimidin‐4(1H)‐one, 3‐(1‐methyl‐1H‐pyrrol‐2‐yl)‐3‐oxopropanenitrile and aromatic aldehydes to produce new pyrido[2,3‐d]pyrimidine derivatives, in refluxing EtOH with excellent yield (90–97%) and short reaction time (8–13 min). The nanocatalyst was used and recycled in eight runs without significant leaching or loss of its catalytic activity. [ABSTRACT FROM AUTHOR]

A convenient, practical, green, and environmentally friendly method was developed for the synthesis of biscoumarins and corresponding tetrakis products from the reaction of 4‐hydroxycoumarin and various aldehydes. The bis‐coumarins were synthesized in high yield under mild reaction conditions. Products were obtained in the presence of in situ prepared Fe(SD)3 [Iron(III) dodecyl sulfate] as a combined Lewis acid–surfactant catalyst (LASC) in water in short reaction times. Also, the antibacterial activity of compounds was screened against Pseudomonas aeruginosa and Escherichia coli as Gram‐negative bacteria and Micrococcus luteus and Staphylococcus aureus as Gram‐positive bacterial strains. Products 3g, 3k–l were most active than cefotaxime against E. coli and also compounds 3c and 3g were most active than cefotaxime against S. aureus. [ABSTRACT FROM AUTHOR]

A series of novel bis‐thiazoles were synthesized through a one‐pot semi‐five‐component reaction of the prepared α‐bisbromo ketones, aldehydes, and thiosemicarbazide in the presence of p‐TsOH under reflux condition. Products were obtained in reasonable yields via an efficient, convenient, and simple setup. The inhibitory activity on bacterial growth of the products was studied against Gram‐negative (Escherichia coli and Pseudomonas aeruginosa) and Gram‐positive bacterial strains (Micrococcus luteus, Staphylococcus aureus) at different concentrations (25, 50, 100, and 200 μg/mL at 600 nm). Most of the products showed inhibitory activity at the concentration of 200 μg/mL. In addition, bis‐thiazoles showeed high to moderate antioxidant activity using the diphenylpicrylhydrazyl (DPPH) method. Bis‐thiazoles 6i and 6j showed higher antioxidant activity than vitamin C and vitamin E. A series of novel bis‐thiazoles were synthesized through a one‐pot semi‐five component reaction of the prepared α‐bisbromo ketones, aldehydes, and thiosemicarbazide in the presence of p‐TsOH under reflux condition. Most of the products showed good to excellent inhibitory activity against Gram negative and Gram‐positive bacterial strains. The bis‐thiazoles showed high to moderate antioxidant activity using (DPPH) method. [ABSTRACT FROM AUTHOR]

A convenient, practical, green, and environmentally friendly method was developed for the synthesis of benzothiazoles from 2-aminothiophenol and various aldehydes. Bis-benzothiazoles were synthesized in high yield under mild reaction conditions. Products were obtained in the presence of in situ prepared Fe(SD)3 [iron(III) dodecyl sulfate] as a combined Lewis acid-surfactant catalyst (LASC) in water under ultrasound irradiation. [ABSTRACT FROM AUTHOR]

An efficient synthesis of pyrido[2,3- d]pyrimidine derivatives via one-pot multicomponent reactions of 6-amino-2-(alkylthio)pyrimidin-4(3 H)-one, 3-cyanoacetylindole and arylaldehydes using [Fe3O4@ZrO2] as magnetically recyclable nanocatalyst is reported. This protocol furnished the desired products in good to excellent yields (70-93 %) and lower reaction times. The catalyst could be easily and efficiently separated from the final product solution by an external magnet and be reused in 5 consecutive runs without any significant activity decrease. [ABSTRACT FROM AUTHOR]