Once released to the environment, pesticides may be degraded by abiotic and biotic processes. While parent compounds are assessed in detail in many regulatory schemes, the requirements for the assessment of transformation products are less well developed. This study was therefore performed to explore the relationships between the toxicity of transformation products and their parent compounds an...

in this investigation, continuous cooling transformations and microstructures have been studied in detail in a low carbon ti-nb bearing microalloyed steel by means of dilatometry, metallography and hardness measurements. the results indicate that when the cooling rate is greater than 1˚c/s, the dilatation curve is associated with a major dilatation at relatively low transformation temperatures,...

In this paper, the synthesis of various enaminones from the reaction of 3-aminocoumarin and ethyl-2,4-dioxo-4-arylbutanoate in the presence of p-toluene sulfonic acid is reported. The reaction was examined under different solvents and catalytic systems, which clearly proved the importance of acidic catalyst in this organic transformation. This work was also accompanied by density functional the...

Selective transformation of 2-propargylthio-6-methyl-pyrimidin-4(1H)On e (2) to 3,5-dimethyl-7H-thiazolo [3,2-a] pyrimidin-7-one (3) is performed under the conditionof base catalysis . For elucidation of structure, palladium catalyzed cyclization reaction of (2) was carried out and the structures of the products were assigned (5) and (6). These compounds underwent isomerization to (3) and (4...

In this research, a sol gel autocaombustion route has been proposed to synthesize alumina-zirconia composite powders, using ammonium bicarbonate as a new fuel. Then the effect of calcination temperature on phase transformation and crystallite sizes was investigated. To characterize the products XRD, TEM and BET analyses were used. XRD patterns of as-synthesized powder and calcined powders at 11...

An overview of the use of olefin cross-metathesis in the synthesis of biologically active natural products is presented. The diverse examples are organized according to the outcome of the olefin constructed by the cross-metathesis reaction: this olefin can be either present in the final product, reduced, engaged in other transformations, or involved in tandem processes.

MgO nanopartticels (NP-MgO) in average size between 30—130 nm were prepared by sonochemistry method. Some phenols have been converted to ortho-hydroxybezaldehyd by ortho-formylation using MgO nanoparticles and (CH2O)n in xylene and subsequently treated with aqueous NH2OH.HCl, affording the corresponding aldoxime in a one-pot procedure. Moreover, this one-pot process, with two transformations, o...

Microbial transformation has been successfully applied in the production of steroid intermediates with therapeutic use and commercial value in pharmaceutical industry due to its high regio- and stereo-selectivity. As such, it is still important to screen microbial strains with novel activity or more efficient abilities in the development of the commercial steroid industry. Biotransformation of ...