Synthesis of 2,3-dihydroquinazolin-4(1H)-ones from anthranilamide and ketones over Hβ zeolite in aqueous media*

The synthesis of 2,3-dihydroquinazolin-4(1H)-ones by cyclocondensation of anthranilamide with ketones in aqueous media using Hβ zeolite is reported. The scope of the reaction was explored by various ketones such as aromatic, aliphatic and cyclic ketones. Based on the preliminary mechanistic results, a tentative mechanism for the formation of 2,3-dihydroquinazolin-4(1H)-ones using zeolite catalyst (Hβ) is predicted. The reusability study, large-scale experiment and water as solvent showed significant benefits of this catalytic protocol in comparing to earlier methods.     

Catalyst-free one-pot synthesis of benzimidazoles from 1,2-diaminoarenes and alcohols

A new and efficient protocol is described for the one-pot synthesis of benzimidazoles from a variety of aryl alcohols and 1,2-diaminoarenes. The yields were ranging from moderate to excellent. Moreover, the present method is utilizing alcohols instead of aldehydes and the reactions are carried out under solvent- and catalyst-free conditions, offering an environmentally benign process.     

Studies of Metals in Crocodilians by Spectrochemical Methods

Abstract: This review covers the results of metal determinations using various spectrochemical analytical techniques in crocodilians from various geographical regions. The most widely determined metal is mercury, both inorganic and organic. However, many other metals, including the known toxic metals of lead and cadmium, have been determined. In general, more elevated levels of metals have been determined in crocodilians from potentially contaminated as opposed to more pristine areas. Significant differences in concentrations for many metals have been demonstrated in captive versus wild alligators. The part of crocodilians most widely utilized for food, tail or tail meat, has attracted the most interest, but studies on kidney and liver as well as blood have been reported. Eggs and hatchings have also been examined for several metal concentrations.     

Regio- and stereoselective co-iodination of olefins using NH4I and Oxone

A simple, efficient, and environmentally benign protocol for the synthesis of vicinal iodohydrins and iodoesters from olefins using NH₄I and Oxone in CH₃CN/H₂O (1:1) and dimethylformamide (DMF) / dimethylacetamide (DMA), respectively, without employing a catalyst at room temperature is described. Regio- and stereoselective iodohydroxylation and iodoesterification of various olefins with anti fashion, following Markonikov’s rule, was achieved and the corresponding products were obtained in good to excellent yields. In addition, 1,2-disubstituted olefins afforded excellent diastereoselectivity.     

Catalyst-free synthesis of amines from cyclic ketones and formamides in superheated water

A novel and environmentally benign protocol for the synthesis of amines from cyclic ketones and formamides is demonstrated. The reaction proceeds under catalyst-free and superheated water conditions and yields range from poor to excellent.     

Extensively Reversible Thermal Transformations of a Bistable,Fluorescence‐Switchable Molecular Solid: Entry into Functional Molecular Phase‐Change Materials

Functional phase‐change materials (PCMs) are conspicuously absent among molecular materials in which the various attributes of inorganic solids have been realized. While organic PCMs are primarily limited to thermal storage systems, the amorphous–crystalline transformation of materials like Ge‐Sb‐Te find use in advanced applications such as information storage. Reversible amorphous–crystalline transformations in molecular solids require a subtle balance between robust supramolecular assembly and flexible structural elements. We report novel diaminodicyanoquinodimethanes that achieve this transformation by interlinked helical assemblies coupled with conformationally flexible alkoxyalkyl chains. They exhibit highly reversible thermal transformations between bistable (crystalline/amorphous) forms, along with a prominent switching of the fluorescence emission energy and intensity.     

Effect of synthesis time and treatment on porosity of mesoporous silica materials

Nitrogen adsorption at 77 K on mesoporous silica materials (MPS) with varying synthesis time and treatment conditions was investigated. Scanning electron microscope (SEM) and X-ray diffraction (XRD) were also used to characterize the mesoporous materials. This study was performed at 6, 24 and 72-h synthesis times. It is shown that 6-h is not enough for complete formation of the MPS material and at least 24-h is necessary. The pore structure starts decaying for the 72-h synthesis time. The three-after-synthesis treatment conditions used were 1) washed, 2) washed and calcined and 3) directly calcined after synthesis. Ethanol/HCl mixtures were used for washing and calcinations were performed at 550°C. Among these samples, directly washed sample yields the lowest adsorption capacity while washed and calcined sample yields the highest adsorption capacity. Hence, it is concluded that washing stabilizes the structure before high temperature treatment.     

Synthesis and antiproliferative activity of 6,7-aryl/hetaryl coumarins

Two different series of novel analogs of 6,7-aryl/hetaryl coumarins 4a–4h and 8i–8l have been synthesized by using Suzuki–Miyara cross coupling reaction from 4-methyl-2-oxo-2H-chromen-7-yl trifluoro-methanesulfonate and 4-methyl-2-oxo-2H-chromen-6-yl trifluoromethanesulfonate in high yields (70–90%). All synthesized compounds were elucidated by means of IR, ¹H NMR, ¹³C NMR, and MS spectra. The synthesized compounds were tested for antiproliferative activity against different human cancer cell lines (SiHa, MDAMB-231, and PANC-1) and some of products demonstrated the distinctive effect.