Very fast and efficient synthesis of some novel substituted 2-arylbenzimidazoles in water using ZrOCl2·nH2O on montmorillonite K10 as catalyst

Abstract  A simple and eco-friendly protocol for the synthesis of some novel substituted 2-arylbenzimidazoles was developed. In this process, these compounds were prepared in water as the solvent using ZrOCl₂·nH₂O supported on montmorillonite K10 as an efficient water tolerating Lewis acid. The reaction was performed under mild conditions with good to excellent yields and remarkable chemoselectivity in the absence of any byproduct. Graphical Abstract        

Cell Uptake of Lipid‐Coated Diamond

Fluorescent nanodiamonds (FNDs) can be used as nanoscale magnetic resonance sensors and stable optical labels. As a first step for using FNDs as nanosensors inside cells, they have to be ingested. Several techniques that improve particle uptake have been used. A simple approach based on commercially available liposomes is used to improve uptake. Uptake into colon cancer cells (HT‐29 cells) is demonstrated. Additionally, it is shown for the first time that one can facilitate diamond uptake into yeast cells by removing the cell wall and creating a so‐called spheroplast. Finally, the characteristics of FNDs coated with lipids and their behavior inside the cells are evaluated.     

Non-asymptotic superlinear convergence of standard quasi-Newton methods

Mathematical Programming - In this paper, we study and prove the non-asymptotic superlinear convergence rate of the Broyden class of quasi-Newton algorithms which includes the...     

A mild and highly efficient method for the synthesis of 5‐aryl‐(N‐phenyl‐)6H‐1,3,4‐thiadiazin‐2‐aminium salts using reusable heterogeneous catalysts

5‐Aryl‐6H‐1,3,4‐thiadiazin‐2‐aminium and 5‐aryl‐N‐phenyl‐6H‐1,3,4‐thiadiazin‐2‐aminium salts have efficiently been synthesized from the reaction of thiosemicarbazide and α‐haloketones in acetonitrile at room temperature using i) silica supported sodium hydrogen sulfate and ii) silica sulfuric acid as reusable heterogeneous catalysts. The experimental procedure is simple and the products are obtained in high yields.     

Unexpected Spiroproducts from the Reaction of N‐Benzoylglycine with Ortho‐Formylbenzoic Acids −3,5′‐Dioxo‐2′‐Phenyl‐1,3‐Dihydrospiro[Indene‐2,4′‐[1,3]Oxazol]‐1‐yl Acetates: Establishments of Their Structure

This paper describes a method of preparation of new 3,5′‐dioxo‐2′‐phenyl‐1,3‐dihydrospiro[indene‐2,4′‐[1,3]oxazol]‐1‐yl acetate and its 5‐chloro‐ and bromoderivatives as products of interaction of N‐benzoylglycine (hippuric acid) with corresponding ortho‐formylbenzoic acids. The reaction carried out in acetic anhydride media in the presence of piperidine as catalyst. The novel spirocompounds were purified by column chromatography from multicomponent reaction mixtures. The composition of the spiro‐products was confirmed by C, H, N element analysis. The structure was established by IR, MS, ¹H‐ and ¹³C‐NMR analysis including COSY ¹H‐¹³C experiments.     

Secondary amines immobilized inside magnetic mesoporous materials as a recyclable basic and oxidative heterogeneous nanocatalyst for the synthesis of trisubstituted pyrimidine derivatives

Research on Chemical Intermediates - A novel magnetic MCM-41 nanocomposite-based catalyst is reported for the first time in the multicomponent synthesis of trisubstituted pyrimidines in which...     

Aqueous NaHSO4 catalyzed regioselective and versatile synthesis of 2-thiazolamines

The green acidic catalyst NaHSO₄ was used for the synthesis of some novel substituted 2-thiazolamines in water under mild conditions in high regioselectivity. Correspondence: Shahnaz Rostamizadeh, Department of Chemistry, Faculty of Sciences, K.N. Toosi University of Technology, P. O. Box: 15875-4416, Tehran, Iran.     

A green one-pot synthesis of 3(5)-substituted 1,2,4-triazol-5(3)-amines as potential antimicrobial agents

Journal of the Iranian Chemical Society - An efficient procedure was proposed for the synthesis of 3(5)-substituted 1,2,4-triazol-5(3)-amines via a one-pot reaction of thiourea, dimethyl sulfate...