Zinc chloride silica gel-supported was found to be an efficient, inexpensive catalyst for the synthesis of 1,8-dioxodecahydroacridines via one-pot three-component condensation of aryl aldehydes, dimedone, andammonium acetate in high yields. The described novel synthetic method propose several advantages of safety, mild condition, short reaction times, high yields, simplicityand easy workup comp...

An efficient green route for the preparation of naphthoxazinones, applying a three-component one-pot condensation reaction of 2-naphthol, aromatic aldehyde and urea in the presence of nano silica supported ferric chloride under solvent-free conditions has been developed. The present procedure offers several advantages such as short reaction time, simple workup, recovery and reusability of the c...

Nano-silica supported boron trifluoride (BF3.SiO2) is an efficient, reusable and eco-friendly catalyst for chemoselective thioacetalization of aldehydes and ketones. So, this catalyst was applied for transthioacetalization of acetals and acylals into their corresponding 1,3-dithiolanes or 1,3-dithianes  in good to excellent yields. The reactions were carried out at room temperature under solven...

A series of Fe3O4 supported on mesoporous FDU-12 silica systems were prepared by the hydrothermal conditions. The surface properties of the functionalized catalyst were analyzed by a series of characterization techniques like FTIR, XRD, N2 adsorption–desorption and TEM. XRD and adsorption–desorption analysis shows that the mesostructure of FDU silica remains intact after Fe3O4 modifications, wh...

The method of Zinn & Owens (1986; Canadian Journal of Animal Science 66, 157-166), based on release of purine bases by HClO4 followed by their precipitation with AgNO3, was used to study recovery of purines from lyophilized rumen microbial or Escherichia coli preparations added to matrices such as cellulose, starch and neutral-detergent fibre. The recovery of purines was poor (approximately 50%...

hantzsch 1,4-dihydropyridines are oxidized to the corresponding pyridine derivatives using oxygen or air and a mixture of the manganese and cobalt salts of parninobenzoic acid supported on silica gel as the catalysts. reactions are clean and the catalysts can be recovered easily and reused repeatedly.

Upon performing colorimetric determination of chromium with diphenylcarbazide (DPC), the following were found. The color development proceeded not only in dilute sulphuric acid solution, but also in solutions of HNO3, HCl, HC1O4 and CH3COOH or in mixed solutions of these acids. Wide concentration ranges (about 0.01-0.5 N) of these single acids allowed perfect development of the Cr6+ coloration ...

The faradaic efficiency for O2(g) evolution at thin-filmWO3 photoanodes has been evaluated in a series of acidic aqueous electrolytes. In 1.0 M H2SO4, persulfate was the predominant photoelectrochemical oxidation product, and no O2 was detected unless catalytic quantities of Ag (aq) were added to the electrolyte. In contact with 1.0 M HClO4, dissolved O2 was observed with nearly unity faradaic ...