Alkyl ammonium hydrogen sulfate immobilized on Fe3O4@SiO2 nanoparticles: a highly efficient catalyst for the multi-component preparation of novel tetrazolo[1,5-a]pyrimidine-6-carboxamide derivatives.

In this, a three-component reaction for the preparation of novel tetrazolo[1,5-a]pyrimidine-6-carboxamide derivatives from N,N'-(sulfonylbis(1,4-phenylene))bis(3-oxobutanamide), aldehydes and 1H-tetrazol-5-amine is reported. The application of Fe3O4@SiO2-(PP)(HSO4)2 (A) as a catalyst afforded the desired products (a1-a18) in high yields in DMF as solvent as well as under solvent-free conditions.

Glass-Ceramic Fillers Based on Zinc Oxide-Silica Systems for Dental Composite Resins: Effect on Mechanical Properties.

The potential of glass ceramics as applicable materials in various fields including fillers for dental restorations is our guide to present a new procedure for improvements of the mechanical properties of dental composites. This work aims to use Zn2SiO4 and SiO2-ZnO nano-materials as fillers to improve the mechanical properties of Bis-GMA/TEGDMA mixed dental resins. Zn2SiO4 and SiO2-ZnO samples were prepared and characterized by using XRD, FE-SEM, EDX, and FT-IR techniques. The XRD pattern of the SiO2-ZnO sample shows that ZnO crystallized in a hexagonal phase, while the SiO2 phase was amorphous. Similarly, the Zn2SiO4 sample crystallized in a rhombohedral crystal system. The prepared samples were used as fillers for the improvement of the mechanical properties of Bis-GMA/TEGDMA mixed dental resins. Five samples of dental composites composed of Bis-GMA/TEGDMA mixed resins were filled with 2, 5, 8, 10, and 15 wt% of SiO2-ZnO, and similarly, five samples were filled with Zn2SiO4 samples (2, 5, 8, 10, and 15 wt%). All of the 10 samples (A1-A10) were characterized by using different techniques including FT-IR, FE-SEM, EDX, and TGA analyses. According to the TGA analysis, all samples were thermally stable up to 200 °C, and the thermal stability increased with the filler percent. Next, the mechanical properties of the samples including the flexural strength (FS), flexural modulus (FM), diameter tensile strength (DTS), and compressive strength (CS) were investigated. The obtained results revealed that the samples filled with 8 wt% of SiO2-ZnO and 10 wt% of Zn2SiO4 had higher FS values of 123.4 and 136.6 MPa, respectively. Moreover, 8 wt% of both fillers displayed higher values of the FM, DTS, and CS parameters. These values were 8.6 GPa, 34.2 MPa, and 183.8 MPa for SiO2-ZnO and 11.3 GPa, 41.2 MPa, and 190.5 MPa for the Zn2SiO4 filler. Inexpensive silica-based materials enhance polymeric mechanics. Silica-metal oxide nanocomposites improve dental composite properties effectively.

Barium silicate nanoparticles, an efficient catalyst for one-pot green synthesis of α-benzyl amino coumarin derivatives as potential chemotherapeutic agents.

A new, simple, and efficient method for synthesis of α-benzyl amino coumarin and its derivatives (1-24) is described via a one-pot, three-component condensation of aromatic aldehydes, amine, and 4-hydroxycoumarin under green chemistry conditions: water as a solvent and BaSiO3 nanoparticles as catalyst. BaSiO3 nanoparticles and all synthesized derivatives were characterized by multiple methods including; XRD, NMR, and FE-SEM. This method which gives higher yields, is also less expensive, and more environmentally friendly compared with other methods in the literature. In silico physicochemical and pharmacokinetics analyses were done on all synthesized compounds and indicated that these α-benzyl amino coumarins would be effective scaffolds for the future development of chemotherapeutic agents.

Green Chemistry Preparation of thiochromeno[4,3-b]pyran and benzo[h]thiazolo[2,3-b]quinazoline Derivatives using HSBM Technique over ZnAl2O4 Nano-Powders.

AIM AND OBJECTIVE: The aim of this paper is to introduce HSBM as a green and environmentally friendly technique for the synthesis of thiochromeno[4,3-b]pyran and benzo[h]thiazolo[2,3-b]quinazoline derivatives over ZnAl2O4 nanopowders as an efficient catalyst. MATERIALS AND METHODS: ZnAl2O4 nanopowders were synthesized via a co-precipitation of Zn(NO3)2 and Al(NO3)3 salts and were characterized by XRD, FE-SEM, TEM and DLS techniques. The as-prepared ZnAl2O4 nano-powders have been used as a catalyst on the synthesis of pyran nucleus using high-speed ball milling (HSBM) technique. The structure of products was confirmed with NMR analysis. RESULTS: ZnAl2O4 exhibits a cubic crystal structure (Space group: Fd-3m) with the average crystallite size of 41 nm. The average particle size of ZnAl2O4 nano-powders determined by DLS technique is 55 nm. The catalytic activity of nano-powders was examined on the synthesis of 2- amino-4,5-dihydro-4-arylthiochromeno[4,3-b]pyran-3-carbonitriles, (8Z)-2-amino-8-arylidene-4,5, 7,8-tetrahydro-4-arylthiopyrano[4,3-b]pyran-3-carbonitriles, 4-aryl-3,4,5,6-tetrahydrobenzo[h]quinazoline- 2(1H)-thiones and 4-aryl-1,3,4,5-tetrahydro-2H-thiochromeno[4,3-d]pyrimidine-2-thione derivatives. All products were obtained in high yields with short reaction times. CONCLUSION: ZnAl2O4 nanopowders were prepared via a cost-effective co-precipitation method and showed good potential for the synthesis of 4H-pyran analogous in good yields. The salient advantages of HSBM technique include environmentally friendly with reduced solvents, is a simple technique and has low energy costs.

Effective Removal of Penicillin from Aqueous Solution Using Zinc Oxide/Natural-Zeolite Composite Nano-Powders Prepared Via Ball Milling Technique.

BACKGROUND: The widespread entrance of antibiotics from the pharmaceuticals industry and human medication into aquatic environment increased concern over public health. Due to the importance of the antibiotics removal, a considerable amount of patents reported the conventional methods for the removal of antibiotics from the wastewaters. However, newly of patents reported improvements in the removal capacity. The present study focuses on the removal of Penicillin using a nanocomposite of zinc oxide/natural-Zeolite. METHODS: A nano-composite of zinc oxide/natural-Zeolite was synthesized by mechanical method. The obtained microstructure was characterized by FE-SEM, XRD, EDX, and DLS techniques. The prepared nanocomposite is used for the removal of penicillin from aqueous solution. RESULTS: Two different phases were identified in XRD patterns as hexagonal ZnO and orthorhombic Zeolite with the average crystal size of 86 and 141 nm respectively. The prepared nanocomposite consists of uniform particles with the mean diameter of near 91 nm. The prepared nanocomposite is used for the removal of penicillin from aqueous solution. It exhibited high removal performance in adsorption of penicillin antibiotic. The effects of penicillin concentration, catalyst amount, and pH on the adsorption were studied. The equilibrium adsorption data were analyzed using Langmuir, Temkin and Freundlich equations at room temperature. The Langmuir, Freundlich and Temkin constants were determined as -1.93, 410.2, and 3.87 respectively. The adsorption of Penicillin is followed from Freundlich (R2 = 0.979) equation. Adsorption kinetics followed the intra-particle diffusion model. CONCLUSION: A high efficient procedure for the removal of penicillin was developed using ZnO/ natural-Zeolite nano-composite as useful catalysts.

CuO Nano-structures Prepared in Rosmarinus Officinalis Leaves Extract Medium: Efficient Catalysts for the Aqueous Media Preparation of Dihydropyrano[3, 2-c]chromene Derivatives.

CuO nano-structures were prepared in Rosmarinus Officinalis leaves extract medium via a green bio-chemical method and were used for the one-pot synthesis of dihydropyrano [3,2-c] chromene derivatives. This procedure is very simple and the products were synthesized in high to excellent yields.

Pentafluorophenylammonium triflate (PFPAT) catalyzed facile construction of substituted chromeno[2,3-d]pyrimidinone derivatives and their antimicrobial activity.

A new, simple thermally efficient and solvent-free condensation of 2-amino-3-cyano-6-methyl-4-phenyl-4H-pyran-5-ethylcarboxylate derivatives with coumarin-3-carboxylic acid employing pentafluorophenylammonium triflate (PFPAT) as an inexpensive organocatalyst for the synthesis of a series of ethyl 4,5-dihydro 7-methyl-2-(2-oxo-2H-chromen-3-yl)-4-oxo-5-aryl-3H-chromeno[2,3-d]pyrimidine-6-carboxylate derivatives is described. This method has the advantages of high yields, a cleaner reaction, simple methodology, short reaction times, easy workup, and greener conditions. All the compounds were evaluated for their in vitro antimicrobial activity against different bacterial and fungal strains.

An efficient, simple and expedition synthesis of 1-amidoalkyl-2-naphthols as 'drug like' molecules for biological screening.

An efficient and direct protocol for the preparation of amidoalkyl naphthols employing a multi-component, one-pot condensation reaction of beta-naphthol, aromatic aldehydes and acetamide in the presence of ferric hydrogensulfate under solvent, solvent-free and microwave conditions is described. The thermal solvent-free and microwave green procedures offer advantages such as shorter reaction times, simple work-up, excellent yield, recovery and reusability of catalyst. It is noteworthy that 1-amidomethyl-2-naphthols can be converted into important biological 'drug like' active 1-aminomethyl-2-naphthols derivatives by amide hydrolysis.