A Green Protocol for Simple One‐pot Synthesis of New Pyrimidine Derivatives Both Microwave Irradiation and Conventional Heating: Reactions,Characterization, and Theoretical Calculations

In this research, 5‐benzoyl‐6‐phenyl‐4‐(4‐trifluoromethylphenyl)‐2‐{oxo and thioxo}‐3,4‐dihydro‐1H‐pyrimidines ( 1 , 2 ) were synthesized by using multicomponent cyclocondensation reaction under microwave irradiation and classical heating. Compounds 3 , 4 , 6 , 7 , and 8 obtained reactions of 5‐benzoyl‐6‐phenyl‐4‐(4‐trifluoromethylphenyl)‐2‐thioxo‐3,4‐dihydro‐1H‐pyrimidine ( 1 ) and acetic anhydride, diethyl 2‐bromomalonate, bromoacetic acid, 3‐bromopropionic acid, methyl iodide, respectively. Compound 4 was both acetylated and hydrolyzed in acetic acid to give compound 5 . The structures of all compounds were determined by using spectroscopic techniques like FT‐IR, ¹H/¹³C NMR, and elemental analyses, and the structures of compounds 1 and 3 were analyzed by X‐ray crystal analysis. In addition, the quantum chemical parameters and full geometry optimizations for all compounds were computed using density functional theory based on B3LYP and the 6‐31G (d, p) basis set.     

Cu(I)-catalyzed alkyne–azide ‘click’ cycloaddition (CuAAC): a clean,efficient, and mild synthesis of new 1,4-disubstituted 1H-1,2,3-triazole-linked 2-amino-4,8-dihydropyrano[3,2-b]pyran-3-carbonitrile–crystal structure

Research on Chemical Intermediates - Cu(I)-catalyzed alkyne–azide ‘click’ cycloaddition (CuAAC) is an important ‘‘click chemistry’’ reaction that is widely...     

Synthesis of some novel bis(hetaryl)azo disperse dyes and investigation of their absorption spectra

3‐Amino‐2‐cyano‐4,6‐disubstituted‐thieno{2,3‐b}pyridines and 3‐aminopyridine were diazotized and coupled with 2‐phenylindole, 2‐methylindole, and 1‐methyl‐2‐phenylindole, respectively. These dyes were characterized by UV‐Visible, FT‐IR, ¹H NMR, and mass spectroscopic techniques. Solvent effects on the visible absorption spectra of the dyes were evaluated. The color of the dyes is discussed with respect to the nature of the heterocyclic ring and substituent present therein. In addition, effects of temperature, concentration, as well as acid and base on the visible absorption maxima of the dyes are reported. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:622–630, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20361     

Assessment of radiological hazard parameters due to natural radioactivity in soils from granite-rich regions in Kütahya Province,Turkey

The analysis of natural radioactivity from ²³⁸U, ²³²Th and ⁴⁰K in 357 soil samples collected from the province of Kütahya was carried out using a NaI(Tl) gamma-ray spectroscopy system at the Nuclear Physics Research Laboratory, Dumlup?nar University, Kütahya, Turkey. The specific activities of ²³⁸U, ²³²Th and ⁴⁰K in the soil samples were evaluated. From the activity concentrations of ²³⁸U, ²³²Th and ⁴⁰K, the total absorbed outdoor gamma-ray dose rates and the corresponding annual effective dose rates were determined. The corresponding values of the external and internal hazard indices of all the soil samples were also calculated. The external gamma-ray dose rate at 1 m above the ground was directly measured at each collected soil sample location. The results obtained in this study were compared within the limits of values obtained in other cities of Turkey, those in other countries. Radiological maps of Kütahya Province were constructed from the results of this study.     

Three-dimensional numerical investigation of heat transfer for plate fin heat exchangers

In the present study, the potential of rectangular fins with 30° and 90° angle and 10 mm offset from the horizontal direction for heat transfer enhancement in a plate fin heat exchanger is numerically evaluated with conjugated heat transfer approach. The rectangular fins are mounted on the flat plate channel. The numerical computations are performed by solving a steady, three-dimensional Navier–Stokes equation and an energy equation by using Fluent software program. Air is taken as working fluid. The study is carried out at Re = 400 and inlet temperatures, velocities of cold and hot air are fixed as 300, 600 K and 1.338, 0.69 m/s, respectively. Colburn factor j versus Re design data is presented by using Fluent. The results show that the heat transfer is increased by 10 % at the exit of channel with fin angle of 30° when compared to channel without fin for counter flow. The heat transfer enhancement with fins of 30° and 90° for different values of Reynolds number with 300, 500 and 800 and for varying fin heights, fin intervals and also temperature distributions of fluids on the top and bottom surface of the channel are investigated for parallel and counter flow.     

Oligomeric tetrathiafulvalenes: a new route toward conjugated TTF dimers and trimers

The synthesis of bis-TTF 1 and tris-TTF 2, linked by an ethenyl spacer, is described using new useful Wittig-type reagents with the introduction of phosphonate functionality on 1,3-dithiole and TTF frameworks. Electrochemical and spectroscopic studies show intramolecular electronic interactions between conjugated TTF units.     

Linking the viscous and vacancy behavior of high molecular weight hydrocarbons

A new theoretical model that was recently purposed for zero-shear viscosity has now been extended to the three-branch alkanes with pentyl, hexyl, or phenyl attachments. The model links the equilibrium theory of Simha-Somcynsky (SS) statistical thermodynamics of liquids and the transport theory of Eyring Significant Structure (ESS). The predicted quantity of hole fraction as a measure of the free volume, computed from the SS equation of state, plays a primary role in the theory to combine the both theories. The experimental PVT data from 310 to 408 K temperature and 0.1 to 344.5 MPa pressure range have been used. The proportionality constants of the activation energy and the transmission coefficient have been calculated for each species separately and they are in expected trend with the substituted ring structure. Satisfactory agreement in prediction of viscosity from the hole fraction has been obtained.     

MRI findings of gastric metastases from breast carcinoma

We describe the MR appearance of breast cancer metastases to the stomach. The stomach wall was diffusely thickened with loss of the regular fold pattern best shown on the single shot T2-weighted images and enhanced with moderate mural enhancement on early and late post gadolinium images. The combination of gastric wall thickening and abnormal enhancement should suggest the diagnosis of diffuse mural metastases in a woman with a history of breast cancer.