A convenient method for 14C-labeling of 2-methylthio-1-[4-N-α-ethoxycarbonylbenzyl)-amino-benzyl]-5-hydroxymethyl-2-[14C]-1H-imidazole and 1-[4-N-α-ethoxy-carbonylbenzyl)-aminobenzyl]-5-hydroxymethyl-2-[14C]-1H-imidazole as potential antihypertensives

The key synthetic intermediate, (2-mercapto-1-(4-nitrobenzyl)-1H-imidazol-5-yl)methanol-[2-¹⁴C], has been synthesized by using one pot procedure from potassium[¹⁴C]-thiocyanate. It was converted to two nonpeptide angiotensin II receptor antagonists, 2-methylthio-1-[4-N-α-ethoxycarbonyl benzyl)-aminobenzyl]-5-hydroxymethyl-1H-imidazole-[2-¹⁴C] and 1-[4-N-α-ethoxy-carbonylbenzyl)-aminobenzyl]-5-hydroxymethyl-1H-imidazole-[2-¹⁴C] via a 3-step sequence synthetic pathway.     

Clean synthesis and antibacterial activities of spiro[pyrimido[4,5-b]quinoline-5,5'-pyrrolo[2,3-d]pyrimidine]-pentaones

A simple, clean and efficient method for the synthesis of spiro[pyrimido[4,5-b]quinoline-5,5'-pyrrolo[2,3-d]pyrimidine]-pentaone derivatives by condensation reaction of 6-amino-uracils and isatins in aqueous media is reported. These products were evaluated in vitro for their antibacterial activities.     

Measurement of (liquid + liquid) equilibria for ternary systems of (N-formylmorpholine + benzene + cyclohexane) at temperatures (303.15, 308.15, and 313.15) K

This work demonstrates the ability of N-formylmorpholine (NFM) to act as an extraction solvent for the removal of benzene from its mixture with cyclohexane. The (liquid + liquid) equilibria (LLE) were measured for a ternary system of {N-formylmorpholine (NFM) + benzene + cyclohexane} under atmospheric pressure and at temperatures (303.15, 308.15, and 313.15) K. The experimental distribution coefficients (K) and selectivity factors (S) were obtained to reveal the extractive effectiveness of the solvent for separation of benzene from cyclohexane. The LLE results for the system studied indicate that increasing temperature decreases selectivity of the solvent. The reliability of the experimental results was tested by applying the Othmer–Tobias correlation. In addition, the universal quasichemical activity coefficient (UNIQUAC) and the non-random two liquids equation (NRTL) were used to correlate the LLE data using the interaction parameters determined from the experimental data. The root mean square deviations (RMSDs) obtained comparing calculated and experimental two-phase compositions are 0.0367 for the NRTL model and 0.0539 for the UNIQUAC model.     

A simplified mathematical study of thermochemical preparation of particle oxide under counterflow configuration for use in biomedical applications

This study mathematically presents a counterflow non-premixed thermochemical technique for preparing a particle oxide used for cancer diagnosis and treatment. For this purpose, preheating, reaction, melting, and oxidation processes were simulated considering an asymptotic concept. Mass and energy conservation equations in dimensional and non-dimensional forms were solved using MATLAB^®. To preserve the continuity in the system and calculate the locations of melting and flame fronts, promising jump conditions were derived. In this research, variations in flame temperature, flame front location and mass fractions of the particle, particle oxide and oxidizer, with position, Lewis number and initial temperature of the particles were investigated. The simulation results were compared with those obtained from an earlier experimental study under the same conditions. Regarding the comparison, an appropriate compatibility was observed between the results. Based on the simulation results, flame temperature was found to be about 1310 K. Positions of flame and melting fronts were found to be ??1.8 mm and ??1.78 mm, respectively.

     

One‐Pot Synthesis of Functionalized 2H‐Chromene (=2H‐1‐Benzopyran) Derivatives via a Three‐Component Reaction between a CH‐Acid,a Dialkyl Acetylenedicarboxylate,and Methyl Chloroglyoxylate or Benzyl Carbonochloridate Mediated by Triphenylphosphine

An effective route to functionalized 2H‐chromene (=2H‐1‐benzopyran) derivatives 4 is described (Scheme 1). This involves the reaction of a 1,1‐diactivated alkene, resulting from the reaction of dimedone (=5,5‐dimethylcyclohexane‐1,3‐dione; 1a ) with methyl chloroglyoxylate (ClC(O)COOMe), benzyl carbonochloridate (ClC(O)OCH₂Ph) or 3,5‐dinitrobenzoyl chloride (3,5‐(NO₂)₂C₆H₃C(O)Cl), and a dialkyl acetylenedicarboxylate (=dialkyl but‐2‐ynedioate) in the presence of Ph₃P which undergo intramolecular Wittig reaction to produce 2H‐chromene derivatives (Scheme 1).     

Poly(1,4-butyl-bis-vinylpyridinium) borohydride as a new stable and efficient reducing agent in organic synthesis

The unstable sodium borohydride is stabilized on modified poly(4-vinylpyridinium), and it is used as an efficient and regenerable polymer-supported borohydride reagent for the reduction of a variety of carbonyl compounds, such as aldehydes, ketones, α,β-unsaturated carbonyl compounds, α-diketones and acyloins, in good to excellent yields.     

On-line preconcentration of some rare earth elements in water samples using C18-cartridge modified with l-(2-pyridylazo) 2-naphtol (PAN) prior to simultaneous determination by inductively coupled plasma optical emission spectrometry (ICP–OES)

The on-line column preconcentration technique with inductively coupled plasma optical emission spectroscopy (ICP–OES) has been developed using a cartridge filled with octadecyl silica modified by l-(2-pyridylazo) 2-naphtol (PAN). The aim of this method was to determine some rare earth elements (REEs) (Ce, Dy, La, Sm, and Y) and uranium in water samples. Sample solutions were passed through the C₁₈-modified column. The adsorbed cations were subsequently eluted from the column and transferred into the plasma with nitric acid solution for simultaneous determination of them. Sample pH, amount of PAN as a complexing agent, sampling and eluting flowrates and concentration of the eluent were optimized. Detection limits based on three times of standard deviations of blank by 10 replicates were in the range of 11 ng l⁻¹ for Dy to 69 ng l⁻¹ for U. Sample throughput was 10 samples h⁻¹. The proposed method was applied to determine REEs in natural water samples. Recoveries of the REEs from natural water samples were between 95 and 106% with percent relative standard deviation (%R.S.D.) of 1.0–7.9%.     

Nonmonotonic swelling of agarose‐carbopol hybrid hydrogel: Experimental and theoretical analysis

A hybrid gel is synthesized by physical mixing of agarose and carbopol and an interpenetrating network of Agarose‐Carbopol (AC) hybrid gel is observed by atomic force microscopy. This hybrid gel exhibits pH‐responsiveness and mechanical stability as well as tunable swelling. These hydrogels depict a nonmonotonic swelling behavior as a function of pH. In particular, the equilibrium degree of swelling increases with pH of bath solution until its maximum value around pH = , followed by a decrease at higher pH values. The degree of swelling is increased by the concentration of carbopol when the concentration of agarose is low [ ], or decreased by the concentration of agarose when is high [ ]. A physics‐based model is also adapted to characterize the swelling‐shrinking behavior of different compositions of AC gels. This swelling‐shrinking behavior of AC hydrogels will have potential applications in smart hydrogel‐based devices. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55, 444–454